title: (-)-Epigallocatechin-3-gallate, a potential inhibitor to human dicarbonyl/L-xylulose reductase.
abstract: Dicarbonyl/l-xylulose reductase (DCXR), mainly catalysing the reduction of α-dicarbonyl compounds and l-xylulose, belongs to the short-chain dehydrogenase/reductase superfamily. Its enzyme activity can be inhibited by short-chain fatty acids. In this study, a novel DCXR inhibitor named (-)-epigallocatechin-3-gallate (EGCG) was reported. First, we overexpressed recombinant human DCXR in Escherichia coli, purified the enzyme by affinity chromatography and measured its activity. The inhibition effects of EGCG and its analogues on DCXR were determined subsequently, and EGCG showed the strongest inhibition with 50% inhibition concentration value of 78.8 μM. The surface plasmon resonance analysis also indicated that the equilibrium dissociation constant (KD) reached to 7.11 × 10(-8) M, which implied a high affinity between EGCG and DCXR. From enzyme kinetic analysis, EGCG acted as a mixed inhibitor against its forward and reverse substrates and the coenzyme, reduced nicotinamide adenine dinucleotide phosphate (NADPH). However, the inhibition is pH dependent. The molecular docking finally showed that EGCG formed several hydrogen bonds with the Thr190 residue of DCXR, and the model was further verified by site-directed mutagenesis. Therefore, EGCG is a potential inhibitor to human DCXR.
authors: State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, 220 Handan Road, Shanghai 200433, PR China.
authors: Xiao-Hui
authors: XH
authors: Hu
authors: Li-Ya
authors: LY
authors: Ding
authors: Wei-Xue
authors: WX
authors: Huang
authors: Xian-Mei
authors: XM
authors: Yang
authors: Fang
authors: F
authors: Xie
authors: Min
authors: M
authors: Xu
authors: Long
authors: L
authors: Yu
mesh_terms: D020134:Catalytic Domain; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry*; D004926:Escherichia coli; D015870:Gene Expression; D006801:Humans; D006860:Hydrogen Bonding; D062105:Molecular Docking Simulation; D009249:NADP / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013401:Sugar Alcohol Dehydrogenases / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D009249:NADP; D002392:Catechin; C045651:epigallocatechin gallate; D013401:Sugar Alcohol Dehydrogenases; C023300:L-xylulose reductase
keywords: DCXR; EGCG; SPR; inhibitor; mixed-type