UVM Theses and Dissertations
Format:
Print
Author:
LeBruin, Lyndelle Toni
Dept./Program:
Chemistry
Degree:
MS
Abstract:
Collagen is the main component of mammalian structural protein and also has a unique tertiary structure. It is a multimeric protein assembled from single polypeptide chains which contain the repeating trimer units (Gly-X-Y)n, where proline is strongly favord at the "X" position. In order to investigate the structure and biological activities of natural collagen, short, coHagen-like peptide provide a synthetically tractable model system. These collagen-like peptides are much shorter than natural collagen chains and many strategies have been pursued to stabilize their triple helical structure. These have included connecting three strands by covalent linkages through the use of templates, disulfides, and transition metals.
Our approach to this self assembly process utilizes metal ion ligand chemistry where the ligands are 2,2'-bipyridyl bidentate analogues. Our work has shown that in the presence of Ni (II), three short collagen-like peptides can spontaneously assemble into triple helical structures. The systems were designed to select an optimally stable heterotrimer and mimic the staggered amino acid register ofnatural collagen. We have explored the influence of electronic effects between the metal and ligand and peptide length on the selection of an optimal triple helical moiety from an equilibrium mixture of homotrimers. Our results show that equilibrated heterotrimers with high stabilities are accessible using metal assisted assembly and that trimer composition and stability are contingent upon the, peptide length, metal-ligand chemistry and steric relationships within individual collagen strands.
Our approach to this self assembly process utilizes metal ion ligand chemistry where the ligands are 2,2'-bipyridyl bidentate analogues. Our work has shown that in the presence of Ni (II), three short collagen-like peptides can spontaneously assemble into triple helical structures. The systems were designed to select an optimally stable heterotrimer and mimic the staggered amino acid register ofnatural collagen. We have explored the influence of electronic effects between the metal and ligand and peptide length on the selection of an optimal triple helical moiety from an equilibrium mixture of homotrimers. Our results show that equilibrated heterotrimers with high stabilities are accessible using metal assisted assembly and that trimer composition and stability are contingent upon the, peptide length, metal-ligand chemistry and steric relationships within individual collagen strands.