EP1815009A2 - Méthode de conception de polypeptides pour la nanofabrication de films, de revêtements et de microcapsules fins par autoassemblage électrostatique couche par couche - Google Patents

Méthode de conception de polypeptides pour la nanofabrication de films, de revêtements et de microcapsules fins par autoassemblage électrostatique couche par couche

Info

Publication number
EP1815009A2
EP1815009A2 EP04821431A EP04821431A EP1815009A2 EP 1815009 A2 EP1815009 A2 EP 1815009A2 EP 04821431 A EP04821431 A EP 04821431A EP 04821431 A EP04821431 A EP 04821431A EP 1815009 A2 EP1815009 A2 EP 1815009A2
Authority
EP
European Patent Office
Prior art keywords
amino acid
acid sequence
amino acids
thin film
polypeptides
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04821431A
Other languages
German (de)
English (en)
Other versions
EP1815009A4 (fr
Inventor
Donald T. Haynie
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Louisiana Tech University Foundation Inc
Original Assignee
Louisiana Tech University Foundation Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Louisiana Tech University Foundation Inc filed Critical Louisiana Tech University Foundation Inc
Priority to EP10155610A priority Critical patent/EP2193800A1/fr
Priority to EP10155609A priority patent/EP2193799A1/fr
Publication of EP1815009A2 publication Critical patent/EP1815009A2/fr
Publication of EP1815009A4 publication Critical patent/EP1815009A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/68—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
    • A61P7/06—Antianaemics
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y5/00—Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K1/00—General methods for the preparation of peptides, i.e. processes for the organic chemical preparation of peptides or proteins of any length
    • C07K1/107—General methods for the preparation of peptides, i.e. processes for the organic chemical preparation of peptides or proteins of any length by chemical modification of precursor peptides
    • C07K1/113—General methods for the preparation of peptides, i.e. processes for the organic chemical preparation of peptides or proteins of any length by chemical modification of precursor peptides without change of the primary structure
    • C07K1/1133—General methods for the preparation of peptides, i.e. processes for the organic chemical preparation of peptides or proteins of any length by chemical modification of precursor peptides without change of the primary structure by redox-reactions involving cystein/cystin side chains
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/001—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof by chemical synthesis
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • C07K14/46—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates
    • C07K14/47—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates from mammals
    • C07K14/4701—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates from mammals not used
    • C07K14/4723—Cationic antimicrobial peptides, e.g. defensins

Definitions

  • the present invention relates to the fabrication of ultrathin multilayered films on suitable surfaces by electrostatic layer-by-layer self assembly ("ELBL"). More specifically, the present invention relates to a method for designing polypeptides for the nanofabrication of thin films, coatings, and microcapsules by ELBL for applications in biomedicine and other fields.
  • ELBL electrostatic layer-by-layer self assembly
  • ELBL is an established technique in which ultrathin films are assembled by alternating the adsorption of oppositely-charged polyelectrolytes. The process is based on the reversal of the surface charge of the film after the deposition of each layer.
  • Figure 1 shows a schematic diagram of the general ELBL process: films of oppositely charged polyions (cationic polyions 10 and anionic polyions 11) are assembled in successive layers on a negatively-charged planar surface 12; the surface charge is reversed after the deposition of each layer. This process is repeated until a film of desired thickness is formed.
  • the physical basis of association is electrostatics — gravitation and nuclear forces play effectively no role.
  • ELBL Electrostatic Layer-by- Layer Assembly of Proteins and Polyions
  • Protein Architecture Interfacial Molecular Assembly and Immobilization Biotechnology, Y. Lvov & H. M ⁇ hwald eds. (New York: Marcel Dekker, 1999), pp.125-167, which is incorporated herein by reference in its entirety.
  • ELBL has recently become a focus area in the field of nanotechnology because it can be used to fabricate films substantially less than 1 micron in thickness. Moreover, ELBL permits exceptional control over the film fabrication process, enabling the use of nanoscale materials and permitting nanoscale structural modifications. Because each layer has a thickness on the order of a few nanometers or less, depending on the type of material used and the specific adsorption process, multilayer assemblies of precisely repeatable thickness can be formed.
  • a number of synthetic polyelectrolytes have been employed in ELBL applications, including sodium poly(styrene sulfonate) (“PSS”), ⁇ oly(allylamine hydrochloride) (“PAH”), poly(diallyldimethylammonium chloride) (“PDDA”), poly(acrylamide-co- diallyldimethylammonium chloride), poly(ethyleneimine) (“PEI”), poly(acrylic acid) (“PAA”), poly(anetholesulfonic acid), polyvinyl sulfate) (“PVS”), and poly(vinylsulfonic acid).
  • PSS sodium poly(styrene sulfonate)
  • PAH poly(diallyldimethylammonium chloride)
  • PEI poly(acrylamide-co- diallyldimethylammonium chloride)
  • PEI poly(ethyleneimine)
  • PAA poly(acrylic acid)
  • PVS poly(anetholesulfonic acid)
  • Proteins being polymers with side chains having ionizable groups, can be used in ELBL for various applications, including biomedical ones.
  • proteins that have been used in ELBL include cytochrome c, hen egg white lysozyme, immunoglobulin G, myoglobin, hemoglobin, and serum albumin (ibid.).
  • cytochrome c hen egg white lysozyme
  • immunoglobulin G immunoglobulin G
  • myoglobin myoglobin
  • hemoglobin hemoglobin
  • serum albumin ibid.
  • polypeptides which are generally smaller and less complex than proteins, constitute an excellent class of material for ELBL assembly, and polypeptide film structures formed by ELBL will be useful in a broad range of applications.
  • the present invention provides a method for designing polypeptides for the nanofabrication of thin films, coatings, and microcapsules by ELBL.
  • Polypeptides designed using the method of the present invention should exhibit several useful properties, including, without limitation, completely determined primary structure, minimal secondary structure in aqueous solution, monodispersity, completely controlled net charge per unit length, ability to form cross-links on demand, ability to reverse cross-link formation, ability to form more organized thin films than is possible with proteins, and relatively inexpensive large-scale production cost (assuming gene design, synthesis, cloning, and host expression in E. coli or yeast, or peptide synthesis).
  • Polypeptides designed using the method of the present invention have been shown useful for ELBL of thin film structures with targeted or possible applications in biomedical technology, food technology, and environmental technology. Such polypeptides could be used, for example, to fabricate artificial red blood cells, drug delivery devices, and antimicrobial films.
  • the present invention provides a novel method for identifying "sequence motifs" of a defined length and net charge at neutral pH in amino acid sequence information for use in ELBL, and recording a desired number of the motifs.
  • the method comprises the steps of: (a) Obtaining an amino acid sequence for a peptide or a protein from a particular organism; (b)
  • Locating a starter amino acid in the amino acid sequence (c) Examining the starter amino acid and the following n amino acids to determine the number of charged amino acids having a polarity opposite the certain polarity; (d) If the number of the charged amino acids having a polarity opposite the certain polarity is one or more, continuing the method at step g; (e) Examining the starter amino acid and the following n amino acids to determine the number of charged amino acids having the certain polarity; (f) If the number of charged amino acids having the certain polarity is equal to or greater than x, recording the amino acid sequence motif consisting of the starter amino acid and the following n amino acids; (g) Locating another starter amino acid in the amino acid sequence; and (h) Repeating the method beginning at step c until the desired number of amino acid sequence motifs have been identified or all of the amino acids in the amino acid sequence have been used as the starter amino acid in step c; wherein x is greater than or equal to approximately one-half of n.
  • the present invention also provides a novel method for designing a polypeptide for use in ELBL, comprising the steps of: (a) Identifying and recording one or more amino acid sequence motifs having a net charge of a certain polarity using the steps mentioned in the preceding paragraph and (b) Joining a plurality of said recorded amino acid sequence motifs to form a polypeptide.
  • the present invention also provides a novel method for designing a polypeptide for use in ELBL comprising the following steps: (a) Designing de novo a plurality of amino acid sequence motifs, wherein said amino acid sequence motifs consist of n amino acids, at least x of which are positively charged and none is negatively charged, or at least x of which are negatively charged and none is positively charged, wherein x is greater than or equal to approximately one-half of n; and (b) Joining said plurality of said amino acid sequence motifs.
  • the amino acid sequence motifs can comprise the 20 usual amino acids or non- natural amino acids, and the amino acids can be either left-handed (L-amino acids) or right handed (D-amino acids).
  • the present invention also provides a thin film, the film comprising a plurality of layers of polypeptides, the layers of polypeptides having alternating charges, wherein the polypeptides comprise at least one amino acid sequence motif consisting of n amino acids, at least x of which are positively charged and none is negatively charged, or at least x of which are negatively charged and none is positively charged, wherein x is greater than or equal to approximately one-half of n.
  • the motifs in these polypeptides may be selected using either of the methods described above.
  • the present invention also provides a novel process for using cysteine or other sulfhydryl-containing amino acid types to "lock" and "unlock” the layers of polypeptide ELBL films. This process enables the films to remain stable at extremes of pH, giving greater control over the mechanical stability and diffusive properties of films nanofabricated from designed polypeptides and increasing their utility in a broad range of applications.
  • Figure 1 is a schematic diagram of the general ELBL process.
  • Figure 2 is a graph of the cumulative secondary structure propensities of the amino acid sequence motifs identified in human amino acid sequence information using the method of the present invention, compared with the distribution of structure propensities of 10 5 random amino acid sequences.
  • Figure 3 (a) shows adsorption data as monitored by the quartz crystal microbalance technique ("QCM") for a combination of amino acid sequences designed according to the present invention.
  • Figure 3(b) shows a comparison of adsorption data as monitored by QCM for different combinations of amino acid sequences designed according to the present invention.
  • Figure 3(c) shows a graph of adsorbed mass in nanograms versus layer number for amino acid sequences designed and fabricated according to the present invention.
  • Figure 4(a) illustrates intra-layer disulfide bonds according to the cysteine locking method of the present invention.
  • Figure 4(b) illustrates inter-layer disulfide bonds according to the cysteine locking method of the present invention.
  • Figure 4(c) illustrates the oxidation and reduction of disulfide bonds in microcapsules fabricated from polypeptides designed according to the method of the present invention.
  • Figure 5 is a schematic of the selection process of the present invention used to identify in existing amino acid sequence information amino acid sequence motifs having suitable electrostatic properties for ELBL.
  • Figure 6 shows the number of non-redundant sequence motifs identified in available human amino acid sequence data.
  • Figure 7 shows the ELBL adsorption of poly-L-glutamate and poly-L-lysine from an aqueous medium as a function of ionic strength.
  • Figure 8 shows the adsorption of polypeptides designed according to the method of the present invention for experiments to probe the effect of disulfide bond formation.
  • Figure 9 shows the percentage of material remaining during thin film disassembly at acidic pH as discussed with reference to Figure 8.
  • Figure 10 shows the percentage of material lost during the acidic pH disassembly step of an experiment involving de 7r ⁇ vo-designed polypeptides containing cysteine.
  • Figure 1 l(a) illustrates the role of solution structure of peptides on film assembly, showing how the assembly behavior of poly-L-glutamate and poly-L-lysine depends on pH.
  • QCM resonant frequency is plotted against adsorption layer.
  • the average molecular mass of poly-L-glutamate was 84,600 Da, while that of poly-L-lysine was 84,000 Da.
  • the numbers refer to pH values.
  • the peptide concentration used for assembly was 2 mg/mL.
  • Figure 1 l(b) illustrates the role of solution structure of peptides on film assembly, showing how the solution structure of poly-L-glutamate and poly-L-lysine depends on pH. Mean molar residue ellipticity is plotted as a function of pH.
  • the peptide concentration was 0.05 mg/mL.
  • Figure 12 shows adsorption data for polyelectrolytes of different lengths, illustrating that long polyelectrolytes adsorb better than short ones.
  • immune response means the response of the human immune system to the presence of a substance in the bloodstream.
  • An immune response can be characterized in a number of ways, for example, by an increase in the bloodstream of the number of antibodies that recognize a certain antigen.
  • Antibodies are proteins made by the immune system, and an antigen is an entity that generates an immune response.
  • the human body fights infection and inhibits reinfection by increasing the number of antibodies in the bloodstream. The specific immune response depends somewhat on the individual, though general patterns of response are the norm.
  • epitope means the structure of a protein that is recognized by an antibody. Ordinarily an epitope will be on the surface of a protein.
  • a “continuous epitope” is one that involves several amino acids in a row, not one that involves amino acid residues that happen to be in contact in a folded protein.
  • sequence motif and “motif mean an amino acid sequence of a given number of residues identified using the method of the current invention. In a preferred embodiment, the number of residues is 7.
  • amino acid sequence and “sequence” mean any length of polypeptide chain that is at least two amino residues long.
  • residue means an amino acid in a polymer; it is the residue of the amino acid monomer from which the polymer was formed.
  • Polypeptide synthesis involves dehydration — a single water molecule is “lost” on addition of the amino acid to a polypeptide chain.
  • designed polypeptide means a polypeptide designed using the method of the present invention, and the terms “peptide” and “polypeptide” are used interchangeably.
  • primary structure means the linear sequence of amino acids in a polypeptide chain
  • secondary structure means the more or less regular types of structure stabilized by non-covalent interactions, usually hydrogen bonds — examples include ⁇ -helix, /3-sheet, and /3-turn.
  • amino acid is not limited to the 20 naturally occurring amino acids; the term also refers to D-amino acids, L-amino acids, and non-natural amino acids, as the context permits.
  • non-natural amino acids means amino acids other than the 20 naturally occurring ones.
  • GIu glutamic acid
  • Phe phenylalanine
  • GIy glycine
  • the present invention provides a method for designing polypeptides for the nanofabrication by ELBL of thin films, coatings, and microcapsules for applications in biomedicine and other fields.
  • the method involves 5 primary design concerns: (1) the electrostatic properties of the polypeptides; (2) the physical structure of the polypeptides; (3) the physical stability of the films formed from the polypeptides; (4) the biocompatibility of the polypeptides and films; and (5) the bioactivity of the polypeptides and films.
  • the first design concern, electrostatics is perhaps the most important because it is the basis of ELBL. Without suitable charge properties, a polypeptide will not be soluble in aqueous solution and cannot be used for the ELBL nanofabrication of films.
  • the secondary structure of the polypeptides used for ELBL is also important, because the physical properties of the film, including its stability, will depend on how the solution structure of the peptide translates into its structure in the film.
  • Figure 11 illustrates how the solution structure of certain polypeptides correlates with film assembly.
  • Panel (a) shows how the assembly behavior of poly-L-glutamate and poly-L-lysine depends on pH. It is clear that the ⁇ -helix conformation correlates with a greater extent of deposited material than the ⁇ - sheet conformation. The precise molecular interpretation of this behavior remains to be elucidated.
  • Panel (b) shows how the solution structure of these peptides depends on pH. At pH 4.2 poly-L-glutamate is largely ⁇ -helical, as is poly-L-lysine at pH 10.5. Both polypeptides are in a largely unstructured coil-like conformation at pH 7.3.
  • the remaining concerns relate to the applications of the polypeptide films. In practicing the invention, more or less weight will be placed on these other concerns depending on the design requirements of a particular application.
  • the selection process of the present invention to identify in amino acid sequence information amino acid sequence motifs having suitable charge characteristics, and using the other design concerns to select particular motifs, one can design polypeptides suitable for the ELBL fabrication of nano-organized films for applications in biomedicine arid other fields.
  • NCBI Biotechnology Information's
  • the key selection criterion is the average charge per unit length at neutral pH (pH 7, close to the pH of human blood).
  • pH 7 the average charge per unit length at neutral pH
  • each amino acid sequence motif consist of only 7 residues.
  • the motif length of 7 was chosen in an effort to optimize biocompatibility, physical structure, and the number of non-redundant sequence motifs in available amino acid sequence data. As discussed below, it is preferred that at least half of the amino acid residues in each sequence motif be charged. Moreover, it is preferred that all of the charged residues in each motif be of the same charge. These requirements ensure that each motif will be sufficiently soluble in aqueous solvent and have sufficient charge at neutral pH to be useful for ELBL. Because only a relatively small percentage of amino acid types are charged, as the length of a given amino acid sequence increases, the odds decrease that the sequence will have a sufficient percentage of appropriately charged amino acids for ELBL. 4 charged amino acids is the preferred minimum for a motif size of 7, because fewer than 4 charges yields substantially decreased peptide solubility and decreased control over ELBL.
  • each identified sequence motif is long enough at 7 residues to constitute a continuous epitope (relevant to the possible immune response of an organism into which a designed peptide might be introduced), but not so long as to correspond substantially to residues both on the surface of a protein and in its interior; the charge requirements help to ensure that the sequence motif occurs on the surface of the folded protein; a charged residue cannot be formed in the core of a folded protein.
  • a very short motif could appear to the body to be a random sequence, or one not specifically "self,” and therefore elicit an immune response.
  • the ideal length of a peptide for generating antibodies is a point of some dispute, most peptide antigens range in length from 12 to 16 residues.
  • Peptides that are 9 residues or shorter can be effective antigens; peptides longer than 12 to 16 amino acids may contain multiple epitopes (Angeletti, R.H. (1999) Design of Useful Peptide Antigens, J. Biomol. Tech. 10:2-10, which is hereby incorporated by reference in its entirety). Thus, to minimize antigenicity one would prefer a peptide shorter than 12 and, better yet, shorter than 9 residues.
  • the preferred motifs should not be too long for another reason: to minimize secondary structure formation. Secondary structure decreases control of the physical structure of the polypeptides (see below) and the films made from them.
  • Figure 6 shows the number of non-redundant sequence motifs in available human amino acid sequence information.
  • the greatest number of positive motifs is for a 5-residue length, while the greatest number of negative motifs is for a 7- residue length.
  • the greatest number of positive and negative motifs is about the same for 5 and 7.
  • a motif length of 7 residues would appear to maximize the number of non- redundant motifs.
  • a motif containing both positive and negative amino acids could be useful for ELBL.
  • a slightly longer motif say of 9 residues, could have 6 positively charged amino acids and 1 negatively charged amino acid. It is the balance of charge that is important — the overall peptide must be either sufficiently positively charged or sufficiently negatively charged at neutral pH.
  • Preferred embodiments of the motifs will contain only GIu or Asp or only Arg, His, or Lys as the charged amino acids (although other non-charged amino acids could, and ordinarily do, form part of the motifs), unless non-natural amino acids are admitted as acidic or basic amino acids.
  • Figure 5 is a flow chart showing the steps involved in the selection process for identifying amino acid sequences having suitable electrostatic properties. It is assumed that only the 20 usual amino acids are involved. If searching for negatively-charged motifs, the process begins by locating an amino acid in the sequence data. This amino acid will be called the "starter amino acid” because it is the starting point for the analysis of the surrounding amino acids (i.e., it will begin the motif). Next, the starter amino acid and the following 6 residues are examined for occurrences of Arg, His, or Lys. If one or more Arg, His, or Lys is located in these 7 amino acids, the process is begun anew at another starter amino acid.
  • starter amino acid This amino acid will be called the “starter amino acid” because it is the starting point for the analysis of the surrounding amino acids (i.e., it will begin the motif).
  • the starter amino acid and the following 6 residues are examined for occurrences of Arg, His, or Lys. If one or more Arg, His, or Lys is located in these
  • the 7 amino acids are examined to determine the number of occurrences of GIu and/or Asp. If there are at least 4 occurrences of GIu and/or Asp in the 7 residues, the sequence motif is cataloged. The selection process is essentially the same for positively charged amino acids, except that GIu and Asp are replaced by Arg, His, and Lys, and Arg, His, and Lys are replaced by GIu and Asp, respectively.
  • amino acid sequence amino terminus
  • carboxyl terminus amino acid sequence
  • carboxyl terminus amino acid sequence
  • Glycine has a very low ⁇ -helix propensity and a very low /3-sheet propensity, making it energetically very unfavorable for a glycine and its neighboring amino acids to form regular secondary structure in aqueous solution.
  • Proline has similar properties in some respects and could be used as an alternative to glycine to join motifs.
  • “Summed” propensity means the sum of the ⁇ -helix or /3-sheet propensities of all amino acids in a motif. It is possible, however, that amino acid sequences having a somewhat higher summed ⁇ -helix propensity and/or summed /3-sheet propensity would be suitable for ELBL under some circumstances, as the GIy (or Pro) residues between motifs will play a key role in inhibiting stable secondary structure formation in the designed polypeptide. In fact, it may be desirable in certain applications for the propensity of a polypeptide to form secondary structure to be relatively high, as a specific design feature of thin film fabrication; the necessary electrostatic charge requirements for ELBL must still be met, as discussed above.
  • Structures were selected from the Protein Data Bank (a publicly-accessible repository of protein structures) based on: (a) method of structure determination (X-ray diffraction); (b) resolution (better than 2.0 A) — "resolution” in this context refers to the minimum size of a structure one can resolve, as in the Rayleigh criterion; and (c) structural diversity (less than 50 % sequence identity between the protein crystallographic structures used to compute the helix and sheet propensities of the various amino acids). The rationale was to choose high resolution structures determined by the most reliable methodology and not to bias the propensity calculation by having similar structures. Next, for comparison 100,000 non-redundant random sequences were produced using a random number generator in a personal computer.
  • cysteine or some other type of sulfhydryl- containing amino acid
  • a sequence motif of a designed polypeptide enables the use of relatively short peptides in thin film fabrication, by virtue of intermolecular disulfide bond formation. Without cysteine, such peptides would not generally yield sufficiently stable films (see figure 12, discussed below).
  • cysteine will obviate the need to produce expensive long versions of the designed polypeptides in a substantial percentage of possible applications. This will be particularly advantageous in situations where the thin film is to be fabricated over material to be encapsulated, for example a small crystal of a drug, a small spherical hemoglobin crystal, or a solution containing hemoglobin.
  • amino acid sequence motifs containing cysteine may be selected from the library of motifs identified using the methods discussed above, or designed de novo using the principles described above. Polypeptides can then be designed and fabricated based on the selected or designed amino acid sequence motifs.
  • ELBL assembly of cysteine-containing peptides is done in the presence of a reducing agent, to prevent premature disulfide bond formation. Following assembly, the reducing agent is removed and an oxidizing agent is added. In the presence of the oxidizing agent disulfide bonds form between cysteine residues, thereby "locking" together the polypeptide layers that contain them.
  • This "locking" method may be further illustrated using the following specific example of microcapsule fabrication.
  • designed polypeptides containing cysteine are used to form multilayers by ELBL on a suitably charged spherical surface, normally in aqueous solution at neutral pH and in the presence of dithiothreitol ("DTT"), a reducing agent.
  • DTT dithiothreitol
  • a reducing agent normally in aqueous solution at neutral pH and in the presence of dithiothreitol
  • DTT dithiothreitol
  • the fabrication process is complete and the core particle can thereafter be made to dissolve in the encapsulated environment, for example by a change of pH. If, however, the multilayers are constructed on a "dummy" core particle, the core must be removed. In the case of melamine formaldehyde particles ("MF"), for example, the core is ordinarily dissolved by decreasing the pH — dissolution is acid-catalyzed. Following dissolution of the core, the pH of solution is adjusted to 4, where partial charge on the peptide polyanions makes the microcapsules semi-permeable (compare Lvov et al.
  • MF melamine formaldehyde particles
  • Cysteine can form both intra- and inter-molecular disulfide bonds. Further, disulfide bonds can be formed between molecules in the same layer or adjacent layers, depending on the location of cysteine-containing peptides in the film.
  • cysteine "locking" and “unlocking” is a novel way of regulating the structural integrity and permeability of ELBL films. It is known in the art that glutaraldehyde can be used to cross-link proteins, and this chemical could therefore be used to stabilize polypeptide films. Glutaraldehyde cross-linking, however, is irreversible. In contrast, the cysteine
  • a sulfhydryl could be added to /3-amino acids such as D,L-/3- amino-/3-cylohexyl propionic acid; D,L-3-aminobutanoic acid; or 5-(methylthio)-3- aminopentanoic acid (see http://www.synthatex.com).
  • Biocompatibility is a major design concern in biomedical applications.
  • the practitioner of the present invention will aim to identify genomic or proteomic information that will yield "immune inert" polypeptides, particularly if the fabricated or coated object will make contact with circulating blood.
  • the selection process discussed in Part VII(B)(I) above be used to analyze the amino acid sequences of blood proteins. This will maximize the odds of minimizing the immune response of an organism.
  • a folded globular soluble protein is like an organic crystal, the interior being as densely packed as in a crystal lattice and the exterior being in contact with the solvent, water. Because of their charge properties, the polypeptide sequence motifs identified using the method of the present invention must occur mostly, if not exclusively, on the surface of a protein. Thus, all of the sequence motifs identified in human blood proteins using the selection process of the current invention are effectively always in contact with the immune system while the protein is in the blood. This holds for all conformations of the protein that might become populated in the bloodstream, including denatured states, because it is highly energetically unfavorable to transfer a charge from an aqueous medium to one of low dielectric (as occurs in a protein interior).
  • polypeptides designed from blood proteins using the method of the present invention will either not illicit an immune response or will elicit a minimal immune response.
  • polypeptides designed using the method of the present invention should be biocompatible. All sequence motifs identified from genomic data using the selection process of the current invention, not only those in blood proteins, should be biocompatible, though the extent of immune response or any other type of biological response may well depend on specific details of a sequence motif. (Because the polypeptide sequences on which the motifs are based actually occur in the organism for which the film as been fabricated, this approach will, at least in principle, work equally well for any type of organism.
  • the approach may be of significant value to veterinary science.
  • Both immune response and biocompatibility are important regarding the use of the designed peptides in biomedical applications, including, without limitation, the manufacture of artificial red blood cells, drug delivery systems, or polypeptides for fabrication of biocompatible films to coat implants for short-term or long-term introduction into an organism.
  • a functional domain in this context is an independently thermostable region of a protein that has specific biofunctionality (e.g. binding phosphotyrosine). It is well known in the art that such biofunctionality may be integrated with other functionalities in a multi-domain protein, as for example in the protein tensin, which encompasses a phosphotyrosine binding domain and a protein tyrosine phosphatase domain.
  • biofunctionality e.g. binding phosphotyrosine
  • polypeptides of suitable design are excellent materials for ELBL, and polypeptide film structures formed using ELBL will be useful in a large number of different types of applications.
  • Polypeptides designed using the method of the present invention have been shown to be useful for ELBL of film structures for possible applications in biomedical technology, food technology, and environmental technology. For example, such polypeptides could be used to fabricate artificial red blood cells.
  • Perfluorocarbon emulsions contain synthetic fluorinated hydrocarbons capable of binding oxygen and delivering it to tissues. This approach however, increases reticulo-endothelial cell blockage. The perfluorocarbons can become trapped in the reticulo-endothelial system, which may result in adverse consequences.
  • Another approach focuses on antigen camouflaging, which involves coating red blood cells with a biocompatible polymer called polyethylene glycol (PEG). The PEG molecules form permanent covalent bonds on the surface of the cell.
  • PEG polyethylene glycol
  • the coating effectively hides the antigenic molecules on the surface of the red blood cells, so that the blood recipient's antibodies do not recognize the cells as foreign.
  • the immune system of a normal person who has type A blood will naturally have antibodies that recognize antigens on the surface of type B red blood cells, leading to cell destruction.
  • the attachment of PEG to the surface of a type B red blood cell "camouflages" the surface of the cell, so that its surface antigens can no longer be recognized by the immune system and the antigenically-foreign red blood cells will not be destroyed as quickly (see Pargaonkar, N.A., G. Sharma, and K.K.
  • Unmodified cell-free hemoglobin has known limitations. These include oxygen affinity that is too high for effective tissue oxygenation, a half-life within the intravascular space that is too short to be clinically useful, and a tendency to undergo dissociation into dimers with resultant renal tubular damage and toxicity. Because of these limitations, hemoglobin used to make a cell-free red blood cell substitute must be modified. A number of modification techniques have been developed. Hemoglobin can be cross-linked (a covalent bond between two molecules is made by chemical modification) and polymerized using reagents such as glutaraldehyde.
  • modified hemoglobin is prepared from highly purified hemoglobin and taken through various biochemical processes, to eliminate phospholipids, endotoxins, and viral contaminants (see Nester, T. and Simpson, M (2000) "Transfusion medicine update,” Blood Substitutes, which is hereby incorporated by reference in its entirety).
  • Biopure Corporation (Cambridge, MA) has been using modified hemoglobin for their product, Hemopure.
  • modified hemoglobin solutions The main potential adverse effect of modified hemoglobin solutions is an increase in systemic and pulmonary vascular resistance that may lead to a decrease in cardiac index.
  • Encapsulated hemoglobin has several advantages over cell-free hemoglobin. Firstly, the artificial cell membrane protects hemoglobin from degradative and oxidative forces in the plasma. Secondly, the membrane protects the vascular endothelium from toxic effects of hemoglobin. These relate to heme loss, the production O 2 free radicals and vasoconstrictor effects of NO binding. Thirdly, encapsulation greatly increases the circulating persistence of the hemoglobin. Moreover, encapsulated hemoglobin can be freeze-dried for convenient storage.
  • Liposomal encapsulation involves phospholipids, as in cell membranes.
  • liposomal encapsulation is very difficult to regulate the average size and distribution of liposomes.
  • liposomes are often not very stable, as they ordinarily lack an organized cytoskeleton.
  • liposomes often consist of multiple layers of phospholipid.
  • Red blood cell substitutes employing polypeptides designed using the method of the present invention should offer several advantages over approaches to the development of red blood cell substitutes known in the art, including, without limitation, superior oxygen and carbon dioxide binding functionality, lower production cost (large-scale and therefore low- cost production is possible because bacteria can be used to mass-produce the peptides and because peptide ELBL can be automated), the possibility of using suitable preparations of hemoglobin as a template for ELBL, polypeptide biodegradability, the immune "inertness" of designed polypeptides based on blood protein structure, and the structural stability exhibited by designed polypeptide films, which exceeds that of liposomes.
  • Polypeptide ELBL assembly yields semi-porous films, minimizing the amount of material required for fabricating a means of encapsulation and enabling glucose, oxygen, carbon dioxide, and various metabolites to diffuse as freely through the films as a lipid bilayer.
  • other polymers potentially suitable for this purpose have undesirable side effects — for example, polylactide degrades into lactic acid, the substance that causes muscle cramps, and poly (styrene sulfonate) is not biocompatible.
  • Microcapsules could be formed of designed polypeptides to encapsulate hemoglobin to serve as a red blood cell substitute.
  • Hemoglobin polypeptide microcapsules could also be engineered to incorporate enzymes, including superoxide dismutase, catalase, and methemoglobin reductase, which are ordinarily important for red blood cell function.
  • the nanofabricated microcapsules can predictably be dehydrated, suggesting that artificial red blood cells made as described herein could be dehydrated, without loss of function, particularly because hemoglobin can be lyophilized (i.e., freeze-dried) and reconstituted without loss of function, and polyion films are stable to dehydration. This will be important for long-term storage, transport of blood substitutes, battlefield applications (particularly in remote locations), and space exploration.
  • Polypeptides designed using the method of the present invention could also be used for drug delivery.
  • Micron-sized "cores" of a suitable therapeutic material in "crystalline” form can be encapsulated by designed polypeptides, and the resulting microcapsules could be used for drug delivery.
  • the core must be insoluble under some conditions, for instance high pH or low temperature, and soluble under the conditions where controlled release will occur.
  • the surface charge on the crystals can be determined by f-potential measurements (used to determine the charge in electrostatic units on colloidal particles in a liquid medium).
  • the rate at which microcapsule contents are released from the interior of the microcapsule to the surrounding environment will depend on a number of factors, including the thickness of the encapsulating shell, the polypeptides used in the shell, the presence of disulfide bonds, the extent of cross-linking of peptides, temperature, ionic strength, and the method used to assemble the peptides. Generally, the thicker the capsule, the longer the release time — the principle resembles that of gel filtration chromatography.
  • Polypeptides designed using the method of the present invention should offer a number of advantages in the context of drug delivery, including without limitation control over the physical, chemical, and biological characteristics of the microcapsule; the ability to make capsules with a diameter of less than 1 mm, making the capsules suitable for injection; low likelihood of eliciting an immune response; generally high biocompatibility of capsules; control over the diffusive properties of the microcapsules by varying the thickness of the layers and using cysteine, as discussed below; the ability to target specific locations by modification of the microcapsule surface using the highly reactive sulfhydryl groups in cysteine (as is well known in the art, free sulfhydryl groups, free amino groups, and free carboxyl groups are sites to which molecules for specific targeting could be attached), or by incorporation of a specific functional domain in the design of the polypeptide; and the ability of microstructures to be taken up by cells using either endocytosis or pinocytosis.
  • Polypeptides designed using the method of the present invention could also be used for antimicrobial coatings.
  • Antimicrobial Coatings The method of the present invention could be used to manufacture films encompassing antimicrobial peptides.
  • one suitable sequence might be Histatin 5, which occurs in humans:
  • polypeptides designed using the method of the present invention could be useful.
  • Other possible uses for peptides designed using the method of the present invention include without limitation food covers, wraps, and separation layers; food casings, pouches, bags, and labels; food coatings; food ingredient microcapsules; drug coatings, capsules, and microcapsules; disposable food service items (plates, cups, cutlery); trash bags; water-soluble bags for fertilizer and pesticides; microcapsules for fertilizer and pesticides; agricultural mulches; paper coatings; loose-fill packaging; disposable medical products (e.g. gloves and gowns); and disposable diapers. D. Fabrication
  • the designed polypeptide is synthesized using methods well known in the art, such as solid phase synthesis and F-moc chemistry or heterologous expression following gene cloning and transformation.
  • Designed polypeptides may be synthesized by a peptide synthesis company, for example SynPep Corp. (Dublin, California), produced in the laboratory using a peptide synthesizer, or produced by recombinant methods.
  • a designed polypeptide consists of individual amino acid sequence motifs joined in tandem. The same motif may be repeated, or different motifs may be joined in designing a polypeptide for ELBL.
  • amino acids than glycine could be used to link the sequence motifs, and amino acids other than the 20 usual ones could be included in the motifs themselves, depending on the properties desired of the polypeptide. Other properties could likewise be specified by design requirements, using methods known in the art. For example, proline could be included for turn formation, glycine for chain flexibility, and histidine for pH-sensitive charge properties near neutral pH. "Hydrophobic" amino acids could also be included — hydrophobic residue content could play a role in assembly behavior and contribute to layer stability in a way resembling the hydrophobic stabilization of globular proteins.
  • fabricated polypeptides be at least 15 amino acids long, although it is more preferred that the fabricated polypeptides be at least 32 amino acids long.
  • the reason for this is that the entropy loss per molecule is so thermodynamically unfavorable for short polymers that adsorption to an oppositely-charged surface is inhibited, even if the polypeptide has a charge per unit length of 1; long polyelectrolytes adsorb better than short ones. This is illustrated in Figure 12.
  • Example 1 Design of Polypeptides Based on Human Blood Protein
  • polypeptide sequences were:
  • the amino acid residues are represented by the three-letter code given above.
  • One glycine was introduced between each 7-residue motif to inhibit secondary structure formation. Glycine was selected for this purpose because it allows the greatest variability in combination of dihedral angles (see Ramachandran, G.N. and Saisekharan, V. (1968), Adv. Protein Chemistry, 23:283, which is incorporated by reference herein in its entirety) and has a low helix propensity (0.677) and low sheet propensity (0.766).
  • proline could be substituted for glycine between motifs on the basis of calculated structure propensities.
  • polypeptides were named SNl (SEQ ID NO: 2), SP2 (SEQ ID NO: 1), LN3
  • the positive peptides are somewhat more hydrophobic than the negative ones, owing to the presence of valine and the long hydrocarbon side chain of arginine. (As mentioned above, hydrophobic interactions between polypeptide layers could stabilize films to some extent.)
  • the lengths are consistent with published studies showing that polyions must have greater than 20 charged groups (i.e. aspartic acid and glutamic acid; lysine, arginine, and histidine) to be suitable for ELBL (see Kabanov, V. and Zezin, A. (1984) PureAppl. Chem. 56:343 and Kabanov, V. (1994) Polym. Sd. 36: 143, both of which are incorporated by reference herein in their entireties).
  • a. Experimental demonstration i. Materials
  • QCM electrodes (USI-System, Japan) coated with evaporated silver had a surface area of 0.16 ⁇ 0.01 cm 2 on each side, a resonant frequency of 9 MHz (AT-cut), and a long-term stability of ⁇ 2 Hz.
  • the polypeptide molecular weight was verified by electrospray mass spectrometry. Peptide purity was greater than 70 %.
  • the polypeptide buffer was 10 mM sodium phosphate or 10 mM Tris-HCl, 1 mM DTT, 0.1 mM sodium azide, pH 7.4. All chemicals other than polypeptides were purchased from Sigma-Aldrich (USA). ii. Procedures Experiments were done using pairs of designed polypeptides, one negative and one positive.
  • Multilayer films consisting of at least 5 bi-layers of the above-identified SP2, SNl, LP4, and LN3 were deposited onto the QCM resonators using standard ELBL techniques (a bi-layer consists of one layer of polycation and one layer of polyanion).
  • the polypeptide concentration used for layer adsorption was 2 mg-mL ⁇ . It is known that dependence of polyion layer thickness on polyelectrolyte concentration is not strong (see Lvov, Y. and
  • Resonators were rinsed for 1 min. in pure water between subsequent adsorption cycles (removing perhaps 10-15 % of weakly adsorbed material) and dried in a stream of gaseous N 2 . Then the mass of the deposited peptide was measured indirectly by QCM. The mass measurement includes some water, despite drying, and low mass ions like K + , Na + , and CF. Partial interpenetration of neighboring layers of peptide is probable (see Decher, G. (1997)
  • Figure 3 (a) shows a comparison of adsorption data for LP4 and LN3 in different buffers (10 niM sodium phosphate, pH 7.4, 1 mM DTT and 10 niM Tris-HCl, pH 7.4, 1 mM DTT). It is clear from these data that adsorption depends more on the properties of the peptides than the specific properties of the buffer used.
  • Figure 3(b) shows resonator frequency versus adsorbed layer for different combinations of SP2, SNl, LP4, and LN3 (namely, SP2/SN1, SP2/LN3,
  • FIG. 3(c) shows a graph of calculated adsorbed mass versus layer number for SNl and LP4 in 10 mM Tris-HCl, pH 7.4 and 1 mM DTT (calculated from experimental data using the Sauerbrey equation). The total adsorbed mass, approximately 5 ⁇ g, corresponds approximately to 1 nmol of peptide.
  • polypeptides designed using the method of the present invention are suitable for ELBL, despite significant qualitative differences from PSS and PAH, flexible homopolymers having 1 charge per unit length at pH 7.4.
  • the charge per unit length on poly-L-lysine and poly-L-glutamic acid is 1 at pH 7.4, as with PSS and PAH, but both of these polypeptides have a marked propensity to form ⁇ -helical structure under various conditions, making them substantially less suitable for multilayer assembly when control over thin film structure is desired.
  • the monodisperse polypeptides of the present invention enable the practitioner to know, quite precisely, the structure of the material being used for ELBL.
  • poly-L-lysine and poly-L- glutamic acid are polydisperse, and poly-L-lysine, poly-L-glutamic acid, PSS, and PAH evoke an immune response (i.e. are immunogenic) in humans.
  • precursor layers are deposited on a substrate to enhance adsorption of less adsorptive substances.
  • the lack of a precursor layer enhances the biocompatibility of the polyion films because polymers ordinarily used as precursors are immunogenic or allow less precise control over polymer structure or thin film structure than designed polypeptides. Multilayers of the designed polypeptides were stable at the pH of human blood, 7.4.
  • the multilayers should be useful for a broad range of biological applications.
  • Drying is done to get an accurate QCM frequency measurement, but is not required for assembly.
  • salt concentration ionic strength of solution influences thin film assembly.
  • the amount of material deposited per layer increases with ionic strength in the range 0 - 100 mM NaCl.
  • the choice of buffer should not fundamentally alter the stability of the multilayers in their target environment.
  • the "locking" mechanism would be available as a design feature to stabilize the capsule.
  • the usual thin film thickness calculation for proteins and other polymers is probably invalid for short polypeptides (calculated thickness is 60-90 nm, but summed length of 10 polypeptides is approximately 120 nm). This probably results from a high density of packing of the relatively short polypeptides onto the adsorption surface; the result is also consistent with finding that film thickness varies with ionic strength, as changes in structural properties of a polymer will occur and screening of charges by ions will reduce intra-layer charge repulsion between adsorbed peptides.
  • the thickness of the designed polypeptide thin film discussed here is estimated at 20-50 nm.
  • GIy Lys VaI Lys Tyr GIu Cys GIu GIy GIu VaI GIu VaI GIu Cys GIu GIy GIu VaI GIu VaI GIu Cys GIu GIy GIu VaI GIu Cys GIu GIy GIu VaI GIu Cys GIu GIy GIu VaI GIu (SEQ ID NO: 6)
  • AU experiments were conducted at ambient temperature. All assembly experiments using QCM were conducted in the same conditions, except that the samples to undergo oxidation were dried using air instead of nitrogen gas.
  • the assembly conditions were 10 mM Tris-HCl, 10 mM DTT, pH 7.4.
  • the nominal peptide concentration was 2mg/ml.
  • the number of layers formed was 14.
  • Disulfide locking conditions for the oxidizing samples were 10 mM Tris-HCl, 1 % DMSO, saturation of water with air, pH 7.5. The duration of the "locking" step was 6 hours.
  • Conditions for the reducing samples were 10 mM Tris-HCl, 1 mM DTT, saturation of water with nitrogen, pH 7.5. The duration of this step was 6 hours.
  • the net charge on one of the peptides is neutralized and the polypeptide film disassembles due to electrostatic repulsion. Reducing conditions prevent disulfide bond formation. Therefore, the electrostatic attraction between the layers is the only binding force for stabilizing the layers under these conditions.
  • disulfide bonds are formed.
  • disulfide bonds inhibit film disassembly. The results indicate that layer stability at acidic pH is directly affected by the formation of intra- and/or inter-layer disulfide bonds — i.e. between molecules in the same layer, between molecules in adjacent layers, or both.
  • the essential elements of this experiment were a quartz crystal microbalance instrument; silver-coated resonators (9 MHz resonant frequency); the negative 48-residue peptide (LN3) (SEQ ID NO: 4); and a positive 48-residue peptide named "SP5" of the following sequence:
  • SP5 was designed using the process described above in Part VII(B)(I) to analyze the amino acid sequence of the human blood protein lactotransferrin (gi
  • the ELBL buffer was 10 mM Tris, pH 7.4, 10 mM NaCl, and 1 mM DTT.
  • the disassembly buffer was 10 mM KCl, pH 2. 2 mL peptide solutions were prepared for SP5 and LN3 by adding 4 mg of each peptide to 2 mL of the above buffer solution and adjusting the pH of each solution to 7.4; the peptide concentration was 2 mg-mL "1 . b. Procedure for Monitoring Assembly of Polypeptide Layers on
  • Reducing procedures were as follows: (1) The frequency of the resonator was measured and recorded prior to peptide adsorption; (2) The resonator was dipped into the SP5 peptide solution for 20 min.; (3) The resonator was dipped into the SP5 rinse solution for 30 sec; (4) The resonator was removed from the rinse solution and dried using nitrogen gas; (5) The QCM resonant frequency of the resonator was recorded; (6) The resonator was dipped into the LN3 peptide solution for 20 min.; (7) The resonator was dipped into the LN3 rinse solution for 30 sec; (8) The resonator 1 was removed from the rinse solution and dried using nitrogen gas; (9) The QCM resonant frequency of the resonator was recorded; (10)
  • Steps 2 through 9 were repeated until 16 layers were adsorbed onto the resonator.
  • Oxidizing procedures were the same as the reducing procedures, except that the resonator was rinsed in D.I. water instead of the SP5 buffer or the LN3 buffer and dried with air instead of nitrogen before each measurement. c Locking Procedures
  • Reducing procedures were as follows: The resonator was placed in an aqueous solution containing 1 mM DTT for 6 hours. DTT, a reducing agent, inhibited disulfide bond formation.
  • Oxidizing procedures were as follows: The resonator was placed in an air-saturated aqueous solution containing 1 % DMSO for 6 hours. DMSO, an oxidizing agent, promoted disulfide bond formation. d. Disassembly on Resonator i. Solutions
  • Reducing procedures were as follows: (1) The initial resonant frequency of the resonator was measured by QCM and recorded; (2) The resonator was dipped into the reducing disassembly solution for 5 min.; (3) The resonator was rinsed in reducing buffer solution for 30 sec; (4) The resonator was dried with gaseous N 2 ; (5) The resonant frequency of the resonator was measured by QCM and recorded; (6) Steps 2 through 5 were repeated for reading times of 5, 10, 15, 20, 30, 60, and 90 min.
  • Oxidizing procedures were the same as for reducing procedures, except that rinsing of the resonator was done in D.I. water saturated with air instead of reducing buffer. e. Results
  • Figure 8 shows approximately linear increase in mass deposited during thin film assembly of SP5 and LN3. Both resonators show almost identical deposition of mass throughout the process of assembly, despite differences in assembly conditions.
  • Figure 9 shows the percentage of material remaining during film disassembly. The layers subjected to oxidizing conditions showed a minimal loss of material at acidic pH with almost 90 to 95 % of mass retention. By contrast, layers subjected to reducing conditions lost almost all the film material within the first 5 minutes of exposure to acidic pH. f. Conclusions The results demonstrate that at acidic pH, disulfide bonds prevent layer degeneration and hold the layers firmly together. Layer stability at acidic pH is directly affected by the formation of intra- and/or inter-layer disulfide bonds.
  • Disulfide bond formation is dependent on the concentration and proximity of cysteine residues to each other. Increasing the concentration per unit chain length of the polypeptide would therefore directly influence disulfide bond formation and thin film stability. Increasing the ionic strength of the buffer solutions used for film assembly influences the concentration of cysteine in the film by increasing the amount of material deposited per adsorption cycle and the thickness of each layer. The increased number of cysteine amino acids in a single layer would in this way increase the number of disulfide bonds formed, and, on oxidation, increase film stability.
  • Other embodiments of the invention are possible and modifications may be made without departing from the spirit and scope of the invention. Therefore, the detailed description above is not meant to limit the invention. Rather, the scope of the invention is defined by the appended claims.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Molecular Biology (AREA)
  • Medicinal Chemistry (AREA)
  • Proteomics, Peptides & Aminoacids (AREA)
  • Biophysics (AREA)
  • Biochemistry (AREA)
  • Nanotechnology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Genetics & Genomics (AREA)
  • Hematology (AREA)
  • General Chemical & Material Sciences (AREA)
  • Biotechnology (AREA)
  • General Physics & Mathematics (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Gastroenterology & Hepatology (AREA)
  • Analytical Chemistry (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Urology & Nephrology (AREA)
  • Immunology (AREA)
  • Biomedical Technology (AREA)
  • Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Zoology (AREA)
  • Microbiology (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Diabetes (AREA)
  • Veterinary Medicine (AREA)
  • Toxicology (AREA)
  • Cell Biology (AREA)
  • Public Health (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Animal Behavior & Ethology (AREA)
  • Food Science & Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)

Abstract

L'invention concerne une méthode de conception de polypeptides pour la nanofabrication de films, de revêtements et de microcapsules fins par autoassemblage électrostatique couche par couche pour des applications dans le domaine biomédical et dans d'autres domaines.
EP04821431A 2004-11-22 2004-11-22 Méthode de conception de polypeptides pour la nanofabrication de films, de revêtements et de microcapsules fins par autoassemblage électrostatique couche par couche Withdrawn EP1815009A4 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP10155610A EP2193800A1 (fr) 2004-11-22 2004-11-22 Procédé de conception de polypeptides pour la nanofabrication de films minces, de revêtements et de microcapsules par auto-assemblage couche après couche
EP10155609A EP2193799A1 (fr) 2004-11-22 2004-11-22 Procédé de conception de polypeptides pour la nanofabrication de films minces, de revêtements et de microcapsules par auto-assemblage couche après couche

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2004/039209 WO2006057633A2 (fr) 2004-11-22 2004-11-22 Methode de conception de polypeptides pour la nanofabrication de films, de revetements et de microcapsules fins par autoassemblage electrostatique couche par couche

Publications (2)

Publication Number Publication Date
EP1815009A2 true EP1815009A2 (fr) 2007-08-08
EP1815009A4 EP1815009A4 (fr) 2010-01-27

Family

ID=36498374

Family Applications (3)

Application Number Title Priority Date Filing Date
EP10155610A Withdrawn EP2193800A1 (fr) 2004-11-22 2004-11-22 Procédé de conception de polypeptides pour la nanofabrication de films minces, de revêtements et de microcapsules par auto-assemblage couche après couche
EP10155609A Withdrawn EP2193799A1 (fr) 2004-11-22 2004-11-22 Procédé de conception de polypeptides pour la nanofabrication de films minces, de revêtements et de microcapsules par auto-assemblage couche après couche
EP04821431A Withdrawn EP1815009A4 (fr) 2004-11-22 2004-11-22 Méthode de conception de polypeptides pour la nanofabrication de films, de revêtements et de microcapsules fins par autoassemblage électrostatique couche par couche

Family Applications Before (2)

Application Number Title Priority Date Filing Date
EP10155610A Withdrawn EP2193800A1 (fr) 2004-11-22 2004-11-22 Procédé de conception de polypeptides pour la nanofabrication de films minces, de revêtements et de microcapsules par auto-assemblage couche après couche
EP10155609A Withdrawn EP2193799A1 (fr) 2004-11-22 2004-11-22 Procédé de conception de polypeptides pour la nanofabrication de films minces, de revêtements et de microcapsules par auto-assemblage couche après couche

Country Status (8)

Country Link
EP (3) EP2193800A1 (fr)
JP (1) JP2008520661A (fr)
CN (1) CN101421416B (fr)
AU (1) AU2004325199B2 (fr)
CA (1) CA2587643C (fr)
IL (4) IL183215A (fr)
MX (1) MX2007006099A (fr)
WO (1) WO2006057633A2 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5460332B2 (ja) * 2007-01-22 2014-04-02 アーティフィシャル セル テクノロジーズ インコーポレイテッド ポリペプチドフィルムおよび方法
JP5991966B2 (ja) * 2011-04-25 2016-09-14 大鵬薬品工業株式会社 ｐＨ応答性ペプチドを含むナノ粒子
CN105456233B (zh) * 2015-11-17 2018-04-24 中国石油大学(华东) 一种高载药量的长效缓释抗菌薄膜及其制备方法
CN108133816A (zh) * 2016-03-20 2018-06-08 李忠波 一种防菌抗腐蚀的变压器
CN109346235A (zh) * 2016-03-20 2019-02-15 李忠波 一种输电用防霉防菌抗腐蚀电缆
CN110681324B (zh) * 2019-10-18 2021-11-30 东北石油大学 一种氧化石墨烯杂化多壁自润滑微纳胶囊及其制备方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU7121198A (en) * 1997-04-18 1998-11-13 California Institute Of Technology Multifunctional polymeric tissue coatings
DE69904307T2 (de) * 1998-03-19 2003-09-04 Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften E.V. Herstellung von mit mehrlagen gestrichenen partikeln und hohlen schalen durch elektrostatische selbstorganisierung von nanokompositmehrlagen auf zersetzbaren schablonen
US6833192B1 (en) * 1999-06-10 2004-12-21 Max-Planck Gesellschaft Zur Forderrung Der Wissenschaften E.V. Encapsulation of crystals via multilayer coatings
EP1074563A1 (fr) * 1999-08-02 2001-02-07 F. Hoffmann-La Roche Ag Polypeptides chimériques augmentant la formation de dimères par des interactions électrostatiques et des ponts disulfures, méthode pour les produire et leurs utilisations
WO2004069169A2 (fr) * 2003-01-31 2004-08-19 Scimed Life Systems, Inc. Distribution localisee d'un medicament au moyen de nanocapsules chargees de medicament
US7348399B2 (en) * 2003-08-29 2008-03-25 Louisiana Tech University Foundation, Inc. Nanofabricated polypeptide multilayer films, coatings, and microcapsules

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
HAYNIE DONALD T ET AL: "Polypeptide multilayer films: role of molecular structure and charge." LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 25 MAY 2004, vol. 20, no. 11, 25 May 2004 (2004-05-25), pages 4540-4547, XP002558809 ISSN: 0743-7463 *
LI BINGYUN ET AL: "Multilayer biomimetics: Reversible covalent stabilization of a nanostructured biofilm" BIOMACROMOLECULES, ACS, WASHINGTON, DC, US, vol. 5, no. 5, 1 September 2004 (2004-09-01), pages 1667-1670, XP002414900 ISSN: 1525-7797 *
See also references of WO2006057633A2 *
YURI LVOV ED - LVOV YURI ET AL: "Electrostatic layer-by-layer assembly of proteins and polyions" 1 January 2000 (2000-01-01), PROTEIN ARCHITECTURE: INTERFACIAL MOLECULAR ASSEMBLY AND IMMOBILIZATION BIOTECHNOLOGY, MARCEL DEKKER, NY, PAGE(S) 125 - 167 , XP001539908 ISBN: 9780824782368 * the whole document * *
ZHENG BIN ET AL: "DESIGN OF PEPTIDES FOR THIN FILMS, COATINGS AND MICROCAPSULES FOR APPLICATIONS IN BIOTECHNOLOGY" JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION, VSP, UTRECHT, NL, vol. 16, no. 3, 1 January 2005 (2005-01-01), pages 285-299, XP008078451 ISSN: 0920-5063 *

Also Published As

Publication number Publication date
CA2587643A1 (fr) 2006-06-01
AU2004325199A1 (en) 2006-06-01
AU2004325199B2 (en) 2011-09-08
JP2008520661A (ja) 2008-06-19
IL208932A0 (en) 2011-01-31
CA2587643C (fr) 2013-09-24
EP1815009A4 (fr) 2010-01-27
CN101421416B (zh) 2013-06-12
IL183215A0 (en) 2007-08-19
WO2006057633A2 (fr) 2006-06-01
IL183215A (en) 2012-09-24
CN101421416A (zh) 2009-04-29
EP2193799A1 (fr) 2010-06-09
IL208934A0 (en) 2011-01-31
IL208932A (en) 2015-09-24
IL208933A0 (en) 2011-01-31
WO2006057633A3 (fr) 2009-04-09
IL208933A (en) 2014-03-31
MX2007006099A (es) 2007-11-07
EP2193800A1 (fr) 2010-06-09

Similar Documents

Publication Publication Date Title
US7348399B2 (en) Nanofabricated polypeptide multilayer films, coatings, and microcapsules
US7893198B2 (en) Multilayer films, coatings, and microcapsules comprising polypeptides
AU2006347951B2 (en) Multilayer films, coatings and microcapsules comprising polypeptides
IL208933A (en) Thin membrane containing multiple layers of unbranched polypeptides
US7550557B2 (en) Multilayer films, coatings, and microcapsules comprising polypeptides
Schuster et al. S-layer proteins as key components of a versatile molecular construction kit for biomedical nanotechnology
JP5460332B2 (ja) ポリペプチドフィルムおよび方法
Zheng et al. Design of peptides for thin films, coatings and microcapsules for applications in biotechnology
MX2008005239A (es) Microcapsulas, recubrimientos y peliculas multicapa que comprenden polipeptidos
Alkassem Imaging Antimicrobial Peptides in Action by Atomic Force Microscopy
Linser Development of new antimicrobial peptides based on the synthetic peptide NK-2

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20070511

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LU MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL HR LT LV MK YU

DAX Request for extension of the european patent (deleted)
R17D Deferred search report published (corrected)

Effective date: 20090409

RIC1 Information provided on ipc code assigned before grant

Ipc: A61K 38/03 20060101AFI20090506BHEP

RIC1 Information provided on ipc code assigned before grant

Ipc: G06F 19/00 20060101ALI20091215BHEP

Ipc: A61K 38/03 20060101AFI20090506BHEP

A4 Supplementary search report drawn up and despatched

Effective date: 20091229

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20100326