193206-74-5Relevant articles and documents
In vitro and ex vivo inhibition of hepatitis a virus 3C proteinase by a peptidyl monofluoromethyl ketone
Morris, Tina S.,Frormann, Sven,Shechosky, Shirley,Lowe, Christopher,Lall, Manjinder S.,Gauss-Mueller, Verena,Purcell, Robert H.,Emerson, Suzanne U.,Vederas, John C.,Malcolm, Bruce A.
, p. 797 - 807 (1997)
Hepatitis A virus (HAV) 3C proteinase is the enzyme responsible for the processing of the viral polyprotein. Although a cysteine proteinase, it displays an active site configuration like those of the mammalian serine proteinases (Malcolm, B. A. Protein Science 1995, 4, 1439). A peptidyl monofluoromethyl ketone (peptidyl-FMK) based on the preferred peptide substrates for HAV 3C proteinase was generated by first coupling the precursor, N,N-dimethylglutamine fluoromethylalcohol, to the tripeptide, Ac-Leu-Ala-Ala-OH, and then oxidizing the product to the corresponding peptidyl-FMK( (Ac-LAAQ'-FMK). This molecule was found to be an irreversible inactivator of HAV 3C with a second-order rate constant of 3.3 x 102 M--1 s-1. 19F NMR spectroscopy indicates the displacement of fluoride on inactivation of the enzyme by the fluoromethyl ketone. NMR spectroscopy of the complex between the 13C-labeled inhibitor and the HAV 3C proteinase indicates that an (alkylthio)methyl ketone is formed. Studies of polyprotein processing, using various substrates generated by in vitro transcription/translation, demonstrated efficient blocking of even the most rapid proteolytic events such as cleavage of the 2A-2B and 2C-3A junctions. Subsequent ex vivo studies, to test for antiviral activity, show a 25-fold reduction in progeny virus production as the result of treatment with 5 μM inhibitor 24 h postinfection.
