Cathepsin L is a key host cysteine protease utilized by coronaviruses for cell entry and is a promising drug target for novel antivirals against SARS-CoV-2. The marine natural product gallinamide A and several synthetic analogues were identified as potent inhibitors of cathepsin L with IC50 values in the picomolar range. Lead molecules possessed selectivity over other cathepsins and alternative host proteases involved in viral entry. Gallinamide A directly interacted with cathepsin L in cells and, together with two lead analogues, potently inhibited SARS-CoV-2 infection in vitro, with EC50 values in the nanomolar range. Reduced antiviral activity was observed in cells overexpressing transmembrane protease, serine 2 (TMPRSS2); however, a synergistic improvement in antiviral activity was achieved when combined with a TMPRSS2 inhibitor. These data highlight the potential of cathepsin L as a COVID-19 drug target as well as the likely need to inhibit multiple routes of viral entry to achieve efficacy.

• MeSH
• antivirové látky chemická syntéza   chemie   farmakologie   MeSH
• biologické přípravky chemická syntéza   chemie   farmakologie   MeSH
• buňky A549 MeSH
• Cercopithecus aethiops MeSH
• COVID-19 metabolismus   MeSH
• farmakoterapie COVID-19 MeSH
• inhibitory cysteinových proteinas chemická syntéza   chemie   farmakologie   MeSH
• kathepsin L antagonisté a inhibitory   metabolismus   MeSH
• kationické antimikrobiální peptidy chemická syntéza   chemie   farmakologie   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• molekulární konformace MeSH
• proteomika MeSH
• SARS-CoV-2 účinky léků   MeSH
• Vero buňky MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

The cysteine protease cathepsin K is a target for the treatment of diseases associated with high bone turnover. Cathepsin K is mainly expressed in osteoclasts and responsible for the destruction of the proteinaceous components of the bone matrix. We designed various fluorescent activity-based probes (ABPs) and their precursors that bind to and inactivate cathepsin K. ABP 25 exhibited extraordinary potency (kinac/Ki = 35,300 M-1s-1) and selectivity for human cathepsin K. Crystal structures of cathepsin K in complex with ABP 25 and its nonfluorescent precursor 21 were determined to characterize the binding mode of this new type of acrylamide-based Michael acceptor with the particular orientation of the dibenzylamine moiety to the primed subsite region. The cyanine-5 containing probe 25 allowed for sensitive detection of cathepsin K, selective visualization in complex proteomes, and live cell imaging of a human osteosarcoma cell line, underlining its applicability in a pathophysiological environment.

• MeSH
• akrylamidy chemická syntéza   chemie   metabolismus   MeSH
• fluorescenční barviva chemická syntéza   chemie   metabolismus   MeSH
• fluorescenční mikroskopie MeSH
• inhibitory cysteinových proteinas chemická syntéza   chemie   metabolismus   MeSH
• katalytická doména MeSH
• kathepsin K antagonisté a inhibitory   chemie   metabolismus   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• racionální návrh léčiv MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH