Abstract: | Trifluoroacetylated peptides are much more potent inhibitors of human leukocyte elastase than the corresponding unblocked, acylated or benzyloxycarbonylated peptides. The most active compound was trifluoroacetyl-Val-Tyr-Val (Ki = 1.3 micron). A number of free and NH2-terminal-substituted peptides exhibited similar affinities for porcine pancreatic and human leukocyte elastase, indicating that these two enzymes must have similar specificity sites. |