Synthesis and Characterization of High Molecular Weight Peptide Polymers and Copolymers Containing L-Dopa Residues

摘要

The sea mussel M. edulis utilizes a polyphenolic protein in its adhesive plaque which contains tandem repeats of variants of a decapeptide sequence. We have chemically synthesized members of several families of peptides (GLUE peptides) related to a decapeptide sequence found in the M. edulis polyphenolic protein and prepared them in high purity for structure-function analyses. Chemical polymerization of model peptides and GLUE peptides using diphenylphosphorylazide (DPPA) activation has provided materials for lap shear adhesive strength tests. DPPA has also been used to prepare block copolymers between GLUE polypeptides and poly(epsilon-amino caproic acid). Concurrent enzymatic oxidation studies with GLUE peptides has given some insight into the crosslinking mechanisms which control relative reactivities of specific amino acid residues towards intramolecular or intermolecular bond formation. Polypeptides with repeating amino acid sequences have also been produced using recombinant DNA techniques. Several expression vectors based on the regulatable P sub L promoter have been developed and successfully employed in preparing synthetic gene cassettes for a collagen analogue, an elastin analogue, or a GLUE polypeptide. Gene stability and gene expression studies with a cloned collagen analogue gene have revealed several potential drawbacks to high level microbial expression of genes with repeating amino acid sequences. (aw)