Amino acids and peptides. XVII. Synthesis of a tridecapeptide corresponding to the sequence 165-177 of T-kininogen (tryptic peptide) containing Gln-Val-Val-Ala-Gly sequence and the relationship between structure and effect on thiol proteinase

Simulation of the inhibitory cystatin surface by a synthetic peptide

An inhibitory dodecameric peptide was designed which tentatively mimics the inhibitory site of cystatin C-like structures. Succinylated and mansylated derivatives were also synthesised and assayed for their inhibiting properties towards papain and rat cathepsins B, H and L. All peptides preferentially inhibit cathepsin L and papain as their naturally occurring inhibitor model. A significant increase in inhibition was obtained after mansylation of the crude peptide with Ki values in the micromolar or 0.1 micromolar range. The use and interest of such peptide inhibitors are discussed.