Reaction mechanism of Amphibacillus xylanus NADH oxidase/alkyl hydroperoxide reductase flavoprotein.

The Journal of Biological Chemistry
Y Niimura, V Massey

Abstract

NADH oxidase from Amphibacillus xylanus is a potent alkyl hydroperoxide reductase in the presence of the small disulfide-containing protein (AhpC) of Salmonella typhimurium. In the presence of saturating AhpC, kcat values for reduction of hydroperoxides are approximately 180 s-1, and the double mutant flavoprotein enzyme C337S/C340S cannot support hydroperoxide reduction (Niimura, Y., Poole, L. B., and Massey, V. (1995) J. Biol. Chem. 270, 25645-25650). Kinetics of reduction of wild-type and mutant enzymes are reported here with wild-type enzyme; reduction by NADH was triphasic, with consumption of 2.6 equivalents of NADH, consistent with the known composition of one FAD and two disulfides per subunit. Rate constants for the first two phases (each approximately 200 s-1) where FAD and one disulfide are reduced are slightly greater than kcat values for AhpC-linked hydroperoxide reduction. The rate constant for the third phase (reduction to the 6-electron level) is too small for catalysis. Only the first phase of the wild-type enzyme occurs with the mutant enzyme. These results and the stoichiometry of NADH consumption indicate Cys337 and Cys340 as the active site disulfide of the flavoprotein and that electrons from FADH2 must pa...Continue Reading

References

Sep 1, 1989·Analytical Biochemistry·P BrissetteV Massey
Apr 1, 1986·European Journal of Biochemistry·H L SchmidtB Limbach
Jun 1, 1988·European Journal of Biochemistry·D CoccoJ V Bannister
Dec 1, 1985·Journal of Biochemistry·Y SaekiK Matsumoto
Oct 12, 1972·Biochimica Et Biophysica Acta·C Little
Jun 1, 1972·Hoppe-Seyler's Zeitschrift für physiologische Chemie·L FlohéE Eichele
Oct 15, 1983·Archives of Biochemistry and Biophysics·J Chaudiere, A L Tappel
Aug 1, 1955·Archives of Biochemistry and Biophysics·Y OGURA

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Citations

Feb 9, 2012·Applied Microbiology and Biotechnology·Liang WangRongrong Jiang
Feb 3, 2000·Free Radical Biology & Medicine·L B PooleY Kamio
Sep 30, 2000·European Journal of Biochemistry·L B PooleM Li Calzi
Feb 24, 2006·Molecular Biology of the Cell·Carolyn S Sevier, Chris A Kaiser
May 14, 2009·The Journal of General and Applied Microbiology·Toshiaki AraiJunichi Nakagawa
Sep 8, 1999·Microbiology and Molecular Biology Reviews : MMBR·A MaraisF Mégraud

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