5b5t
Crystal Structure of Escherichia coli Gamma-Glutamyltranspeptidase in Complex with peptidyl phosphonate inhibitor 1b
Structural highlights
FunctionPublication Abstract from PubMedgamma-Glutamyl transpeptidase (GGT, EC 2.3.2.2) that catalyzes the hydrolysis and transpeptidation of glutathione and its S-conjugates is involved in a number of physiological and pathological processes through glutathione metabolism and is an attractive pharmaceutical target. We report here the evaluation of a phosphonate-based irreversible inhibitor, 2-amino-4-{[3-(carboxymethyl)phenoxy](methoyl)phosphoryl}butanoic acid (GGsTop) and its analogues as a mechanism-based inhibitor of human GGT. GGsTop is a stable compound, but inactivated the human enzyme significantly faster than the other phosphonates, and importantly did not inhibit a glutamine amidotransferase. The structure-activity relationships, X-ray crystallography with Escherichia coli GGT, sequence alignment and site-directed mutagenesis of human GGT revealed a critical electrostatic interaction between the terminal carboxylate of GGsTop and the active-site residue Lys562 of human GGT for potent inhibition. GGsTop showed no cytotoxicity toward human fibroblasts and hepatic stellate cells up to 1mM. GGsTop serves as a non-toxic, selective and highly potent irreversible GGT inhibitor that could be used for various in vivo as well as in vitro biochemical studies. Phosphonate-based irreversible inhibitors of human gamma-glutamyl transpeptidase (GGT). GGsTop is a non-toxic and highly selective inhibitor with critical electrostatic interaction with an active-site residue Lys562 for enhanced inhibitory activity.,Kamiyama A, Nakajima M, Han L, Wada K, Mizutani M, Tabuchi Y, Kojima-Yuasa A, Matsui-Yuasa I, Suzuki H, Fukuyama K, Watanabe B, Hiratake J Bioorg Med Chem. 2016 Aug 31. pii: S0968-0896(16)30667-8. doi:, 10.1016/j.bmc.2016.08.050. PMID:27622749[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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