Molybdopterin in carbon monoxide oxidase from carboxydotrophic bacteria

Journal Article · Wed Feb 01 04:00:00 EST 1984 · J. Bacteriol.; (United States)

OSTI ID:6265237

Meyer, O; Rajagopalan, K V

The carbon monoxide oxidases (COXs) purified from the carboxydotrophic bacteria Pseudomonas carboxydohydrogena and Pseudomonas carboxydoflava were found to be molybdenum hydroxylases, identical in cofactor composition and spectral properties to the recently characterized enzyme from Pseudomonas carboxydovorans. All three enzymes exhibited a cofactor composition of two flavin adenine dinucleotides, two molybdenums, eight irons and eight labile sulfides per dimeric molecule, typical for molybdenum-containing iron-sulfur flavoproteins. The millimolar extinction coefficient of the COXs at 450 nm was 72 (per two flavin adenine dinucleotides), a value similar to that of milk xanthine oxidase and chicken liver xanthine dehydrogenase at 450 nm. That molybdopterin, the novel prosthetic group of the molybdenum cofactor of a variety of molybdoenzymes is also a constituent of COXs from carboxydotrophic bacteria is indicated by the formation of identical fluorescent cofactor derivatives, by complementation of the nitrate reductase activity in extracts of Neurospora crassa nit-1, and by the presence of organic phosphate additional to flavin adenine dinucleotides. Molybdopterin is tightly but noncovalently bound to the protein. COX, sulfite oxidase, xanthine oxidase, and xanthine dehydrogenase each contains 2 mol of molybdopterin per mol of enzyme. The presence of a trichloroacetic acid-releasable, so-far-unidentified, phosphorous-containing moiety in COX is suggested by the results of phosphate analysis.

• Research Organization: Universitaet Goettingen, West Germany
• OSTI ID: 6265237
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 157:2; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
ENZYMES
METABOLISM
METALS
MICROORGANISMS
MOLYBDENUM
NONMETALS
OXIDATION
OXIDES
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PHOSPHORUS
PSEUDOMONAS
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENTS