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1rgq
From Proteopedia
M9A HCV Protease complex with pentapeptide keto-amide inhibitor
Overview
A series of novel peptidyl-alpha-ketoamide compounds were evaluated as inhibitors of the deltaNS3-NS4A serine protease from the hepatitis C virus. These peptidyl-alpha-ketoamide inhibitors with Ki values ranging from 0.17 nM to 5.6 microM exhibited slow-binding inhibition. Kinetic studies established one-step kinetic mechanisms and dissociation rate constants in the 3-7 x 10(-5) s(-1) range for these compounds. The association rate constants, which ranged from 10 to 263,000 M(-1) s(-1), were responsible for the greater than four order of magnitude overall binding affinity range exhibited by this series. An X-ray crystal structure of a protease-inhibitor complex revealed an unusual interaction between the oxyanion of the adduct and the protein as well as a significant movement in the S1' region of the protein loop comprising residues 35-42. These results are quite different from peptidyl-alpha-ketoacid inhibition of HCV protease, which reportedly undergoes no notable conformational changes and proceeds with a two-step slow-binding kinetic mechanism.
About this Structure
1RGQ is a Protein complex structure of sequences from Hepatitis c virus. Full crystallographic information is available from OCA.
Reference
Hepatitis C NS3 protease inhibition by peptidyl-alpha-ketoamide inhibitors: kinetic mechanism and structure., Liu Y, Stoll VS, Richardson PL, Saldivar A, Klaus JL, Molla A, Kohlbrenner W, Kati WM, Arch Biochem Biophys. 2004 Jan 15;421(2):207-16. PMID:14984200 Page seeded by OCA on Sat May 3 07:28:32 2008
