Evaluation of peptide-aldehyde inhibitors using R188I mutant of SARS 3CL protease as a proteolysis-resistant mutant.
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.
Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kita-ku, Kyoto 603-8334, Japan. akaji@koto.kpu-m.ac.jp
Kenichi
K
Akaji
Hiroyuki
H
Konno
Mari
M
Onozuka
Ayumi
A
Makino
Hiroyuki
H
Saito
Kazuto
K
Nosaka
D000447:Aldehydes / Q000138:chemical synthesis / Q000494:pharmacology*; D000595:Amino Acid Sequence; D001665:Binding Sites; D000086782:Coronavirus 3C Proteases; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009154:Mutation / Q000235:genetics; D011480:Protease Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology*; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D045473:Severe acute respiratory syndrome-related coronavirus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D045169:Severe Acute Respiratory Syndrome / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D014764:Viral Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism
D000447:Aldehydes; D011480:Protease Inhibitors; D014764:Viral Proteins; D003546:Cysteine Endopeptidases; D000086782:Coronavirus 3C Proteases