NAD(P)H‐flavin oxidoreductase from the bioluminescent bacterium, Vibrio fischeri ATCC 7744, is a flavoprotein

Abstract

The NAD(P)H-flavin oxidoreductase gene from the bioluminescent bacterium, Vibrio fischeri ATCC 7744, was expressed in Escherichia coli, and the enzyme purified using Cibacron Blue 3G-A affinity column chromatography from crude extracts in a single step. The purified enzyme had a typical flavoprotein absorption spectrum and flavin mononucleotide (FMN) was identified as a prosthetic group, non-covalently bound in a molar ratio of 1:1. The enzyme catalyzed the electron transfer from NADH via FMNH₂ to various other electron acceptors. Reduced flavin produced by flavin reductase participated non-enzymatically in the following reactions: H₂O₂-forming NADH oxidase-like, oxygen-insenstive nitroreductase-like, diaphorase (quinone reductase)-like and bacterial luciferase reactions.