Peptide mimetics possess important advantages in comparison with naturally occurring and physiologically active peptides. Therefore we plan to synthesise pseudopeptides characterised by the replacement of the scissile peptide bond with the transition-state- analogous sulfonamido bond. As monomers we will prepare a large basic set of functionalized N-Boc protected vinylogous y-amino sulfonic acids, which are derived from naturally occurring amino acids like Ser. Asn, Trp etc. The next step will be the development of a solid phase synthesis of the vs-peptide bond using TentaGel-NH2 and a photocleavable linker moiety. This solid phase synthesis will enable us to construct combinatorial libraries containing vinylogous sulfonyl peptides. The screening of the libraries should permit the identification of new lead structures, which will be further optimised as new drugs. We are confident that new inhibitors of the aspartic proteases renin and HlV-protease will be found using this technology.