A broadly based research program aimed at the introduction of the tools of molecular biology into polymer materials science will be carried out. Conventional chemical methods of polymer synthesis are inherently limited by the statistical nature of polymerization processes, and as a result conventional polymeric materials comprise statistical mixtures of chains. The preparation of pure polymeric materials, and the use of polymers in applications that require precise control of molecular and supramolecular structure, can be realized only through the introduction of new synthetic methods. The exploitation of the high fidelity of protein biosynthesis, coupled with recent advances in the synthesis, cloning and expression of genes, will be used to create new polymeric materials of precisely defined structure. The focus will be on two classes of polymers - homopolypeptides and repetitive copolypeptides - that are believed to be of special interest in materials science. The following will be carried out: i) the synthesis of artificial genes that encode such polymers,ii) expression in bacterial hosts of the polymers of interest, and iii) detailed analysis of the molecular and supramolecular structures of the products. Both materials issues (e.g., solid state structure and chain conformation in solid polypeptides) and biological questions (e.g., genetic stability and expression levels) will address in the course of the work. Biological syntheses will be complemented by chemical preparations of analogous polypeptides in order to compare and contrast the two approaches, and to facilitate isolation and structural characterization of the biologically-derived products.
