NAD(P)H-FLAVIN OXIDOREDUCTASE FROM THE BIOLUMINESCENT BACTERIUM, VIBRIO-FISCHERI ATCC-7744, IS A FLAVOPROTEIN

The NAD(P)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 FMNH(2), to various other electron accepters. 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.