Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan.
Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
FEBS Lett. 2022 May;596(9):1214-1224. doi: 10.1002/1873-3468.14337. Epub 2022 Mar 28.
The coronavirus (CoV) disease 2019 (COVID-19) caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has become a worldwide pandemic. The 3C-like protease (3CL ), which cleaves 11 sites including its own N- and C-termini on the viral polyproteins, is essential for SARS-CoV-2 replication. In this study, we constructed the full-length inactive 3CL with N- and C-terminal extensions as substrates for monitoring self-cleavage by wild-type 3CL . We found that the rate-limiting C-terminal self-cleavage rate of SARS-CoV-2 3CL was 35-fold faster than that of SARS-CoV 3CL using the Trx/GST-tagged C145A 3CL substrates. Since self-cleavage of 3CL is the initial step for maturation of other viral proteins, our study suggests more facile SARS-CoV-2 replication than that of SARS-CoV.
由严重急性呼吸系统综合征冠状病毒 2（SARS-CoV-2）引起的 2019 年冠状病毒病（COVID-19）已成为全球性大流行。3C 样蛋白酶（3CL ）可在病毒多蛋白上切割包括自身 N 端和 C 端在内的 11 个位点，是 SARS-CoV-2 复制所必需的。在这项研究中，我们构建了全长无活性的 3CL ，其 N 端和 C 端延伸作为监测野生型 3CL 自身切割的底物。我们发现，使用 Trx/GST 标记的 C145A 3CL 底物，SARS-CoV-2 3CL 的限速 C 端自身切割速率比 SARS-CoV 3CL 快 35 倍。由于 3CL 的自身切割是其他病毒蛋白成熟的初始步骤，因此我们的研究表明 SARS-CoV-2 的复制比 SARS-CoV 更容易。
