This collaborative project between workers at Berkeley and UCSF is designed to produce new polymeric peptides with useful properties. The investigators are all excellent scientists, although all well supported by other grants. In particular Dr. Craik has another NSF grant which duplicates his effort in this proposal. The P.I. has developed enzymatic methods for reacting amino acid esters in organic solvents with free amino acids to generate dipeptides. The approach has been extended to a tetra peptide, but the strategy seems unlikely to produce useful polymers, although it might be practical for short peptides. It should be noted that carboxypeptidase cannot be employed in such syntheses because it does not have and acyl enzyme intermediate. There are some interesting ideas in this proposal, but the practicality of synthesizing polypeptides by these approaches seems minimal.