Open AccessThe (2 R )‐hydroxycarboxylate‐viologen‐oxidoreductase from Proteus vulgaris is a molybdenum‐containing iron‐sulphur protein
Author(s) -
TRAUTWEIN Thomas,
KRAUSS Friedrich,
LOTTSPEICH Friedrich,
SIMON Helmut
Publication year - 1994
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1994.tb18954.x
Subject(s) - chemistry , pterin , cofactor , oxidoreductase , molybdenum cofactor , isoelectric point , cyanide , enzyme , flavin mononucleotide , molybdenum , substrate (aquarium) , metalloprotein , stereochemistry , biochemistry , inorganic chemistry , biology , ecology
An oxidoreductase with an extremely broad substrate specificity reducing reversibly 2‐oxocar‐boxylates at the expense of reduced artificial redox mediators to (2 R )‐hydroxycarboxylates has been purified to a specific activity of up to 1800 μmol · min −1 · mg −1 for the reduction of phenylpyruvate. The membrane‐bound non‐pyridine nucleotide‐dependent enzyme appears in the form of various oligomers of the 80‐kDa monomer. The isoelectric point is 5.1. Based on a molecular mass of 80 kDa the enzyme contains up to one molybdenum, four iron and four sulphur atoms. After growth on 99 Mo‐labelled molybdate, enzyme and radioactivity coincided as shown by gel electrophoresis. Permanganate oxidation delivers 0.7 mol pterin‐6‐carboxylic acid. The molybdenum cofactor is a mononucleotide. The enzyme is inhibited by cyanide. The first 20 amino acids have been determined. The enzyme belongs to the rare group of molybdoenzymes which possess no further prosthetic groups than the iron‐sulphur clusters.