A New Class of Self-Complementary Beta Sheet Oligopeptide- Based Biomaterials

Abstract : Mechanisms and functions of a new class of biological materials discovered through self-assembly of ionic self-complementary oligopeptides were studied, and three types of peptides were classified. Type I peptides undergo intermolecular self-assembly and have alternating ionic hydrophilic and hydrophobic amino acid residues. Side chains of these oligopeptides consist of repetitive positively charged residues arginine and lysine, and negatively charged residues glutamate and aspartate on the hydrophilic surface and alanines on the hydrophobic surface. Charged side chains of the oligopeptides in this class form complementary ionic bonds. These oligopeptides also form exceedingly stable Beta-sheets in water. They have been classified into several modulus, i.e., modulus I, II, III, IV, and mixed moduli, based on the ionic surface of the molecules which have alternating + and - charged amino acid residues. Type II peptides undergo both intermolecular and intramolecular self-assembly. When these peptides are in the Beta-sheet structure, they undergo intermolecular self-assembly. When the Beta-sheet lattice is disrupted by heat or change of pH, they undergo intramolecular self-assembly to form stable monomeric helices. Type III peptides undergo surface self-assembly to form monolayers, modifying their surface properties.