Abstract
The 3C-like protease (3CL(pro)) of severe acute respiratory syndrome associated coronavirus (SARS-CoV) is vital for SARS-CoV replication and is a promising drug target. Recombinant 3CL(pro) was expressed in Pichia pastoris GS115 as a 42 kDa protein that displayed a K ( m ) of 15 ± 2 μM with Dabcyl-KTSAVLQSGFRKME-Edans as substrate. Purified 3CL(pro) was used for inhibition and kinetic assays with seven flavonoid compounds. The IC(50) of six flavonoid compounds were 47-381 μM. Quercetin, epigallocatechin gallate and gallocatechin gallate (GCG) displayed good inhibition toward 3CL(pro) with IC(50) values of 73, 73 and 47 μM, respectively. GCG showed a competitive inhibition pattern with K ( i ) value of 25 ± 1.7 μM. In molecular docking experiments, GCG displayed a binding energy of -14 kcal mol(-1) to the active site of 3CL(pro) and the galloyl moiety at 3-OH position was required for 3CL(pro) inhibition activity.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Catechin / analogs & derivatives
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Catechin / metabolism
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Coronavirus 3C Proteases
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Cysteine Endopeptidases / biosynthesis
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Cysteine Endopeptidases / chemistry
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Cysteine Endopeptidases / genetics
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Flavonoids / metabolism*
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Gene Expression
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Hydrolysis
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Inhibitory Concentration 50
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Kinetics
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Molecular Weight
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Pichia / genetics
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Protease Inhibitors / metabolism*
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Recombinant Proteins / antagonists & inhibitors
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Recombinant Proteins / biosynthesis
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Severe acute respiratory syndrome-related coronavirus / enzymology*
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Severe acute respiratory syndrome-related coronavirus / genetics
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Viral Proteins / antagonists & inhibitors*
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Viral Proteins / biosynthesis
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Viral Proteins / chemistry
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Viral Proteins / genetics
Substances
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Flavonoids
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Protease Inhibitors
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Recombinant Proteins
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Viral Proteins
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gallocatechin gallate
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Catechin
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epigallocatechin gallate
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Cysteine Endopeptidases
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Coronavirus 3C Proteases