Abstract
The 3C-like (3CL) protease of the severe acute respiratory syndrome (SARS) coronavirus is a key enzyme for the virus maturation. We found for the first time that the mature SARS 3CL protease is subject to degradation at 188Arg/189Gln. Replacing Arg with Ile at position 188 rendered the protease resistant to proteolysis. The R188I mutant digested a conserved undecapeptide substrate with a K(m) of 33.8 microM and k(cat) of 4753 s(-1). Compared with the value reported for the mature protease containing a C-terminal His-tag, the relative activity of the mutant was nearly 10(6). Novel peptide-aldehyde derivatives containing a side-chain-protected C-terminal Gln efficiently inhibited the catalytic activity of the R188I mutant. The results indicated for the first time that the tetrapeptide sequence is enough for inhibitory activities of peptide-aldehyde derivatives.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aldehydes / chemical synthesis
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Aldehydes / pharmacology*
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Amino Acid Sequence
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Binding Sites
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Coronavirus 3C Proteases
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Cysteine Endopeptidases / genetics*
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Cysteine Endopeptidases / metabolism
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Humans
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Hydrolysis
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Models, Molecular
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Molecular Sequence Data
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Molecular Structure
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Mutation / genetics
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Protease Inhibitors / chemical synthesis
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Protease Inhibitors / pharmacology*
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Protein Conformation
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Protein Processing, Post-Translational
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Severe Acute Respiratory Syndrome / 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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Severe acute respiratory syndrome-related coronavirus / metabolism
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Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Substrate Specificity
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Viral Proteins / antagonists & inhibitors*
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Viral Proteins / genetics*
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Viral Proteins / metabolism
Substances
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Aldehydes
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Protease Inhibitors
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Viral Proteins
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Cysteine Endopeptidases
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Coronavirus 3C Proteases