skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Identification of the NADH-binding subunit of NADH-ubiquinone oxidoreductase of Paracoccus denitrificans

Journal Article · · Biochemistry; (United States)
DOI:https://doi.org/10.1021/bi00475a015· OSTI ID:5393675
;  [1]
  1. Research Institute of Scripps Clinic, La Jolla, CA (USA)

The NADH dehydrogenase complex isolated from Paracoccus denitrificans is composed of approximately 10 unlike polypeptides and contains noncovalently bound FMN, non-heme iron, and acid-labile sulfide. When the Paracoccus NADH dehydrogenase complex was irradiated by UV light in the presence of (adenylate-{sup 32}P)NAD, radioactivity was incorporated exclusively into one of three polypeptides of M{sub r} {approximately}50,000. Similar results were obtained when (adenylate-{sup 32}P)NADH was used. The labeling of the M{sub r} 50,000 polypeptide was diminished when UV irradiation of the enzyme with (adenylate-{sup 32}P)NAD was performed in the presence of NADH, but not in the presence of NADP(H). The labeled polypeptide was isolated by preparative sodium dodecyl sulfate gel electrophoresis and was shown to cross-react with antiserum to the NADH-binding subunit of bovine NADH-ubiquinone oxidoreductase. Its amino acid composition was also very similar to that of the bovine NADH-binding subunit. These chemical and immunological results indicate that the M{sub r} 50,000 polypeptide is an NADH-binding subunit of the Paracoccus NADH dehydrogenase complex.

OSTI ID:
5393675
Journal Information:
Biochemistry; (United States), Vol. 29:23; ISSN 0006-2960
Country of Publication:
United States
Language:
English