title: Flavonoid-mediated inhibition of SARS coronavirus 3C-like protease expressed in Pichia pastoris.
abstract: The 3C-like protease (3CL(pro)) of severe acute respiratory syndrome associated coronavirus (SARS-CoV) is vital for SARS-CoV replication and is a promising drug target. Recombinant 3CL(pro) was expressed in Pichia pastoris GS115 as a 42 kDa protein that displayed a K                         (                            m                         ) of 15 ± 2 μM with Dabcyl-KTSAVLQSGFRKME-Edans as substrate. Purified 3CL(pro) was used for inhibition and kinetic assays with seven flavonoid compounds. The IC(50) of six flavonoid compounds were 47-381 μM. Quercetin, epigallocatechin gallate and gallocatechin gallate (GCG) displayed good inhibition toward 3CL(pro) with IC(50) values of 73, 73 and 47 μM, respectively. GCG showed a competitive inhibition pattern with K                         (                            i                         ) value of 25 ± 1.7 μM. In molecular docking experiments, GCG displayed a binding energy of -14 kcal mol(-1) to the active site of 3CL(pro) and the galloyl moiety at 3-OH position was required for 3CL(pro) inhibition activity.
authors.affiliation: School of Biological Sciences and Technology and the Research Institute for Catalysis, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 500-757, Republic of Korea.
authors.forename: Thi Thanh Hanh
authors.initials: TT
authors.lastname: Nguyen
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Woo
authors.forename: Hee-Kyoung
authors.initials: HK
authors.lastname: Kang
authors.forename: Van Dao
authors.initials: VD
authors.lastname: Nguyen
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Kim
authors.forename: Do-Won
authors.initials: DW
authors.lastname: Kim
authors.forename: Sul-Ah
authors.initials: SA
authors.lastname: Ahn
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Xia
authors.forename: Doman
authors.initials: D
authors.lastname: Kim
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives / Q000378:metabolism; D000086782:Coronavirus 3C Proteases; D003546:Cysteine Endopeptidases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D005419:Flavonoids / Q000378:metabolism*; D015870:Gene Expression; D006868:Hydrolysis; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008970:Molecular Weight; D010843:Pichia / Q000235:genetics; D011480:Protease Inhibitors / Q000378:metabolism*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D045473:Severe acute respiratory syndrome-related coronavirus / Q000201:enzymology* / Q000235:genetics; D014764:Viral Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics
chemical_list: D005419:Flavonoids; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D014764:Viral Proteins; C417940:gallocatechin gallate; D002392:Catechin; C045651:epigallocatechin gallate; D003546:Cysteine Endopeptidases; D000086782:Coronavirus 3C Proteases