Gabexate mesylate is a non-antigenic synthetic inhibitor of trypsin-like serine proteinases with Ki values of 3.4nM and 180nM, respectively for human tryptase and bovine tryptase [1].
Gabexate mesylate is a drug used in the treatment of pancreatitis, disseminated intravascular coagulation and as a regional anticoagulant for hemodialysis. Gabexate mesylate is reported to bind to the primary specificity site S1 of human and bovine tryptases. The carbonyl group of gabexate mesylate interacts with the oxyanion binding hole of the enzyme. The tighter binding of gabexate mesylate to human tryptase results in a higher affinity than to bovine tryptase [1].
Gabexate mesylate is also found to inhibit cNOS and iNOS, with Ki values of 150μM and 5mM. It up-regulates iNOS gene expression. In addition, gabexate mesylate inhibits the LPS/IFNγ-induced NO production with EC50 value of 250μM [2].
References:
[1] Erba F, Fiorucci L, Pascarella S, Menegatti E, Ascenzi P, Ascoli F. Selective inhibition of human mast cell tryptase by gabexate mesylate, an antiproteinase drug. Biochem Pharmacol. 2001 Feb 1;61(3):271-6.
[2] Colasanti M, Persichini T, Venturini G, Menegatti E, Lauro GM, Ascenzi P. Effect of gabexate mesylate (FOY), a drug for serine proteinase-mediated diseases, on the nitric oxide pathway. Biochem Biophys Res Commun. 1998 May 19;246(2):453-6.