Stable macroscopic membranes formed by self-assembly of amphiphilic peptides and uses therefor
Described herein is the self-assembly of amphiphilic peptides, i.e., peptides with alternating hydrophobic and hydrophilic residues, into macroscopic membranes. The membrane-forming peptides are greater than 12 amino acids in length, and preferably at least 16 amino acids, are complementary and are structurally compatible. Specifically, two peptides, (AEAEAKAK) 2 (ARARADAD) 2 , were shown to self-assemble into macroscopic membranes. Conditions under which the peptides self-assemble into macroscopic membranes and methods for producing the membranes are also described. The macroscopic membranes have several interesting properties: they are stable in aqueous solution, serum, and ethanol, are highly resistant to heat, alkaline and acidic pH, chemical denaturants, and proteolytic digestion, and are non-cytotoxic. The membranes are potentially useful in biomaterial applications such as slow-diffusion drug delivery systems, artificial skin, and separation matrices, and as experimental models for Alzheimer's disease and scrapie infection. The sequence of the peptide, EAK16, was derived from a putative Z-DNA binding protein from yeast, called zuotin. The cloning and characterization of the ZUO1 gene are also described.
1. A drug delivery system comprising:
membranes formed by self-assembly of amphiphilic peptides, wherein the peptides have alternating hydrophobic and hydrophilic amino acids, are complementary and structurally compatible, and self-assemble in the presence of a monovalent cation; and;
a drug.
2. The drug delivery system of claim 1 , wherein the drug is a protein.
3. The drug delivery system of claim 2 , wherein the protein is selected from the group consisting of: erythropoietin, tissue type plasminogen activator, synthetic hemoglobin and insulin.
4. The drug delivery system of claim 1 , wherein the hydrophilic amino acids are acidic and basic amino acids.
5. The drug delivery system of claim 4 , wherein the acidic amino acids are independently selected from the group consisting of aspartic acid and glutamic acid.
6. The drug delivery system of claim 4 , wherein the basic amino acids are independently selected from the group consisting of arginine, lysine, histidine and ornithine.
7. The drug delivery system of claim 1 , wherein the hydrophobic amino acids are selected from the group consisting of alanine, valine, leucine, isoleucine, methionine, phenylalanine, tyrosine, tryptophan, and glycine.
8. A method of delivering a drug to a subject comprising: administering the drug delivery system of claim 1 to the subject.
9. A cell culture system comprising:
membranes formed by self-assembly of amphiphilic peptides, wherein the peptides have alternating hydrophobic and hydrophilic amino acids, are complementary and structurally compatible; and
a cell culture vessel.
10. The cell culture system of claim 9 , wherein the membranes are stacked in the cell culture vessel.
11. The cell culture system of claim 9 , further comprising cells that adhere to surfaces of the membranes.
12. The cell culture system of claim 11 , wherein the cells are engineered to produce a product.
13. The cell culture system of claim 9 , wherein the hydrophilic amino acids are acidic and basic amino acids.
14. The cell culture system of claim 13 , wherein the acidic amino acids are independently selected from the group consisting of aspartic acid and glutamic acid.
15. The cell culture system of claim 13 , wherein the basic amino acids are independently selected from the group consisting of arginine, lysine, histidine and ornithine.
16. The cell culture system of claim 9 , wherein the hydrophobic amino acids are selected from the group consisting of alanine, valine, leucine, isoleucine, methionine, phenylalanine, tyrosine, tryptophan, and glycine.
17. A method of culturing cells comprising steps of:
stacking membranes formed by self-assembly of amphiphilic peptides, wherein the peptides have alternating hydrophobic and hydrophilic amino acids and are complementary and structurally compatible, in a tissue culture vessel in the presence of culture medium, wherein cells adhere to the surfaces of the membranes; and
maintaining the cells under conditions suitable for growth.
18. The method of claim 17 , wherein the cells are engineered to produce a product.
19. The method of claim 18 , further comprising the step of: harvesting the product.
20. A product produced according to the method of claim 19 .
21. A method of treating a subject comprising the step of:
introducing a composition comprising amphiphilic peptides, wherein the peptides have alternating hydrophobic and hydrophilic amino acids, are complementary and structurally compatible, and self-assemble to form a beta-sheet structure in the presence of a monovalent cation, into the subject.
22. The method of claim 21 , wherein the composition comprises a drug.
23. The method of claim 21 , wherein the step of introducing the composition comprises injecting the composition into the subject.