Shindo, N. | bioRxiv Science

bioRxiv2022

Discovery of Chlorofluoroacetamide-Based Covalent Inhibitors for SARS-CoV-2 3CL Protease

The pandemic of coronavirus disease 2019 (COVID-19) has urgently necessitated the development of antiviral agents against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The 3C-like protease (3CLpro) is a promising target for COVID-19 treatment. Here, we report the new class of covalent inhibitors for 3CLpro possessing chlorofluoroacetamide (CFA) as a cysteine reactive warhead. Based on the aza-peptide scaffold, we synthesized the series of CFA derivatives in enantiopure form and evaluated their biochemical efficiencies. The data revealed that 8a (YH-6) with R configuration at the CFA unit strongly blocks the SARS-CoV-2 replication in the infected cells and this potency is comparable to that of nirmatrelvir. The X-ray structural analysis shows that 8a (YH-6) forms a covalent bond with Cys145 at the catalytic center of 3CLpro. The strong antiviral activity and sufficient pharmacokinetics property of 8a (YH-6) suggest its potential as a lead compound for treatment of COVID-19.

biochemistry↗

bioRxiv2020

Prolonged mitosis causes separase deregulation and chromosome nondisjunction

Intercellular karyotype diversity, or aneuploidy, is a widespread feature of cancers propagated through continuous mitotic chromosome segregation errors, the condition called chromosomal instability. The protease separase is an essential enzyme that sever cohesin between sister chromatids, and a probe for separase activity has articulated that separase undergoes abrupt activation shortly before anaphase onset, after being suppressed through metaphase; however the relevance of this robust control remains unclear. In this study, we found that separase activates precociously during prolonged metaphase, consistently in multiple types of cancer cell lines. An artificial extension of metaphase alone in chromosomally stable diploid cells was found to induce precocious activation. These kinetic changes resulted in an incomplete removal of cohesin and emergence of chromosomal bridges in anaphase. Conversely, in transformed cells, shortening back of their prolonged metaphase restored the robust activation of separase and ameliorated anaphase bridge formation. These observations suggest that retarded metaphase progression directly affects the separase activation profile, which provides a previously unanticipated etiology for chromosomal instability in cancers and underscores the significance of the swift mitotic transitions for fail-safe chromosome segregation.Competing Interest StatementThe authors have declared no competing interest.View Full Text

cell biology↗