SARS-CoV-2 3CLpro/3C-like protease Protein

SARS-CoV-2 3CLpro/3C-like protease is a viral cysteine protease that plays a crucial role in the co-translational proteolytic processing of coronavirus polyproteins. Since no homologous proteins with similar cleavage sites exist in the human body, SARS-CoV-2 3CLpro/3C-like protease is a high-quality target for the development of drugs related to COVID-19. SARS-CoV-2 3CLpro/3C-like protease protein is a recombinant, untagged SARS-CoV-2 3CLpro/3C-like protease protein expressed by E.coli^[1][2][3].

SARS-CoV-2 3CLpro/3C-like protease protein is a cysteine protease composed of three domains. Within the cleft between domain I and domain II, it contains the Cys145-His41 catalytic dimer, which cleaves pp1a and pp1ab to generate 12 functional proteins responsible for viral genome replication and transcription. SARS-CoV-2 3CLpro/3C-like protease protein lacks homologous proteins with similar cleavage sites in the human body, effectively reducing off-target risks. Its catalytic pocket is an ideal target for developing anti-coronavirus inhibitors. SARS-CoV-2 3CLpro/3C-like protease protein recognizes its peptide substrates according to the Schechter-Berger nomenclature, with the substrate cleavage site located between P1 and P1'. SARS-CoV-2 3CLpro/3C-like protease protein relies on catalytic dimerization to complete substrate hydrolysis through a multi-step chemical reaction, and can regain its activity after catalysis. Inhibitors of SARS-CoV-2 3CLpro/3C-like protease protein are mainly divided into two categories: covalent inhibitors and non-covalent inhibitors^[1][2][3].

SARS-CoV-2 3CLpro/3C-like protease protein and mutant SARS coronavirus 3CLpro (Q189) are both inhibited by Quercetin (HY-18085), with IC50 values of 42.79 μM and 27.89 μM respectively^[2].
SARS-CoV-2 3CLpro/3C-like protease protein is strongly inhibited by 73 μM Quercetin. This concentration of Quercetin also inhibits recombinant SARS coronavirus 3CLpro expressed by Pichia pastoris, with the inhibition rate of catalytic activities exceeding 80% for both proteins^[2].
SARS-CoV-2 3CLpro/3C-like protease protein can be bound and inhibited by various quercetin glycosides including Rutin (HY-N0148). Quercetin and its metabolites target the dimerization site and regulatory site of this protease to block its function^[2].
SARS-CoV-2 3CLpro/3C-like protease protein is reversibly and competitively inhibited by 4.0 nM EDP-235 (HY-156651), with an apparent inhibition constant (K_i^app) of 3.0 nM. EDP-235 can also inhibit 3CLpro derived from SARS coronavirus, human coronavirus and zoonotic coronavirus, which are homologous to SARS-CoV-2 3CLpro/3C-like protease protein^[3].

Measured by its ability to cleave a fluorogenic peptide substrate Dabcyl-KTSAVLQSGFRKME-Edans and the specific activity is ≥1068.3 nmol/min/mg.

Virus

E. coli

Tag Free

YP_009725301.1 (S1-Q306)

43740578  [NCBI]

Full Length

SGFRKMAFPSGKVEGCMVQVTCGTTTLNGLWLDDVVYCPRHVICTSEDMLNPNYEDLLIRKSNHNFLVQAGNVQLRVIGHSMQNCVLKLKVDTANPKTPKYKFVRIQPGQTFSVLACYNGSPSGVYQCAMRPNFTIKGSFLNGSCGSVGFNIDYDCVSFCYMHHMELPTGVHAGTDLEGNFYGPFVDRQTAQAAGTDTTITVNVLAWLYAAVINGDRWFLNRFTTTLNDFNLVAMKYNYEPLTQDHVDILGPLSAQTGIAVLDMCASLKELLQNGMNGRTILGSALLEDEFTPFDVVRQCSGVTFQ

Approximately 31 kDa, based on SDS-PAGE under reducing conditions.

• 
  ≥ 95%, as determined by reducing SDS-PAGE.

Solution.

Supplied as a 0.22 μm filtered solution of 25 mM HEPES, 2.5 mM DTT, 10% glycerol, pH 7.5.

<1 EU/μg, determined by LAL method.

N/A.

Stored at -80°C for 1 year from date of receipt. It is stable at -20°C for 3 months after opening. It is recommended to freeze aliquots at -80°C for extended storage. Avoid repeated freeze-thaw cycles.

Shipping with dry ice.

• [1]. Chen R, et al. Advances in research on 3C-like protease (3CLpro) inhibitors against SARS-CoV-2 since 2020. RSC Med Chem. 2022 Oct 27;14(1):9-21.

  [2]. Rizky W, et al. The pharmacological mechanism of quercetin as adjuvant therapy of COVID-19. Life Res. 2022 Jan;5(3):17.

  [3]. Rhodin MHJ, et al. The small molecule inhibitor of SARS-CoV-2 3CLpro EDP-235 prevents viral replication and transmission in vivo. Nat Commun. 2024 Aug 1;15:6503.