Crystallographic study on the interaction of L-lactate oxidase with pyruvate at 1.9 Angstrom resolution

• Published in: Biochemical and biophysical research communications Vol. 358; no. 4; pp. 1002 - 1007
• Main Authors: Li, Shu Jie, Umena, Yasufumi, Yorita, Kazuko, Matsuoka, Takeshi, Kita, Akiko, Fukui, Kiyoshi, Morimoto, Yukio
• Format: Journal Article
• Language: English
• Published: United States 13.07.2007
• Subjects: Binding Sites; Computer Simulation; Crystallography - methods; Enzyme Activation; Mixed Function Oxygenases - chemistry; Mixed Function Oxygenases - ultrastructure; Models, Chemical; Models, Molecular; Protein Binding; Protein Conformation; Pyruvic Acid - chemistry; Sensitivity and Specificity
• ISSN: 0006-291X
• DOI: 10.1016/j.bbrc.2007.05.021

L-Lactate oxidase (LOX) from Aerococcus viridans catalyzes the oxidation of L-lactate to pyruvate by the molecular oxygen and belongs to a large family of 2-hydroxy acid-dependent flavoenzymes. To investigate the interaction of LOX with pyruvate in structural details and understand the chemical mechanism of flavin-dependent L-lactate dehydrogenation, the LOX-pyruvate complex was crystallized and the crystal structure of the complex has been solved at a resolution of 1.90 Angstrom. One pyruvate molecule bound to the active site and located near N5 position of FMN for subunits, A, B, and D in the asymmetric unit, were identified. The pyruvate molecule is stabilized by the interaction of its carboxylate group with the side-chain atoms of Tyr40, Arg181, His265, and Arg268, and of its keto-oxygen atom with the side-chain atoms of Tyr146, Tyr215, and His265. The alpha-carbon of pyruvate is found to be 3.13 Angstrom from the N5 atom of FMN at an angle of 105.4 degrees from the flavin N5-N10 axis.