Molecular and Cellular Biochemistry

, Volume 44, Issue 3, pp 181–187

Specificities and properties of three reduced pyridine nucleotide-flavin mononucleotide reductases coupling to bacterial luciferase

  • H. Watanabe
  • J. W. Hastings

DOI: 10.1007/BF00238506

Cite this article as:
Watanabe, H. & Hastings, J.W. Mol Cell Biochem (1982) 44: 181. doi:10.1007/BF00238506


Three different NAD(P)H-FMN reductases were extracted from Beneckea harveyi MB-20 cells and separated by DEAE-Sephadex A50 column chromatography. Further purification was achieved by affinity chromatography. In determinations of Km values for NADH, NADPH, and FMN, these three reductases exhibited different specificities and kinetic parameters. One reductase utilizes NADH, whereas a second one utilizes NADPH as the preferred substrate. The third, a newly described reductase species, exhibits about the same reaction rates with NADH and NADPH. The reaction mechanisms of the three enzyme forms have been deduced by steady state kinetic analysis. The highly pure (based on gel electrophoresis) NADPH-FMN reductase still exhibited a low (approximately 2%) activity for NADH, which activity was increased upon storage at 4° but suppressed completely by the replacement of the phosphate buffer with sodium citrate buffer. This high specificity of NADPH-FMN reductase for NADPH under these conditions is useful for the assay of NADPH, notably in systems coupled to bacterial luciferase.

Copyright information

© Martinus Nijhoff/Dr W. Junk Publishers 1982

Authors and Affiliations

  • H. Watanabe
    • 1
  • J. W. Hastings
    • 1
  1. 1.Biological LaboratoriesHarvard UniversityCambridgeUSA
  2. 2.Laboratory of Applied Botany, Dept. of Agricultural Biology, Faculty of AgricultureKyoto UniversityKyotoJapan