The effect of oxaloacetic acid on tyrosinase activity and structure: Integration of inhibition kinetics with docking simulation.
Oxaloacetic acid (OA) is naturally found in organisms and well known as an intermediate of citric acid cycle producing ATP. We evaluated the effects of OA on tyrosinase activity and structure via integrating methods of enzyme kinetics and computational simulations. OA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type (IC50=17.5±0.5mM and Ki=6.03±1.36mM). Kinetic measurements by real-time interval assay showed that OA induced multi-phasic inactivation process composing with fast (k1) and slow (k2) phases. Spectrofluorimetry studies showed that OA mainly induced regional changes in the active site of tyrosinase accompanying with hydrophobic disruption at high dose. The computational docking simulations further revealed that OA could interact with several residues near the tyrosinase active site pocket such as HIS61, HIS259, HIS263, and VAL283. Our study provides insight into the mechanism by which energy producing intermediate such as OA inhibit tyrosinase and OA is a potential natural anti-pigmentation agent.
College of Biology and Science, Sichuan Agriculture University, Chengdu 611130, PR China.
Lin
L
Gou
Korean Bioinformation Center (KOBIC), Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Nanobiotechnology and Bioinformatics, University of Sciences and Technology, Daejeon 305-350, Republic of Korea.
Jinhyuk
J
Lee
Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region, Institute of Tsinghua University, Jiaxing 314006, PR China.
Hao
H
Hao
Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region, Institute of Tsinghua University, Jiaxing 314006, PR China.
Yong-Doo
YD
Park
College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, PR China. Electronic address: zhanyi_1006@hotmail.com.
Yi
Y
Zhan
Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region, Institute of Tsinghua University, Jiaxing 314006, PR China. Electronic address: lzr7899@163.com.
Zhi-Rong
ZR
Lü
D000364:Agaricus / Q000201:enzymology; D020134:Catalytic Domain / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000378:metabolism* / Q000494:pharmacology*; D007700:Kinetics; D062105:Molecular Docking Simulation; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D062907:Oxaloacetic Acid / Q000378:metabolism* / Q000494:pharmacology*; D012449:Safety
D004791:Enzyme Inhibitors; D062907:Oxaloacetic Acid; D014442:Monophenol Monooxygenase
Inhibition kinetics; Oxaloacetic acid; Tyrosinase