Properties of D-amino-acid oxidase from Rhodotorula gracilis.
The flavoprotein D-amino-acid oxidase was purified to homogeneity from the yeast Rhodotorula gracilis by a highly reproducible procedure. The amino acid composition of the protein was determined; the protein monomer had a molecular mass of 39 kDa and contained one molecule of FAD. The ratio between A274/A455 was about 8.2. D-Amino-acid oxidase from yeast showed typical flavin spectral perturbations on binding of the competitive inhibitor benzoate and was reduced by D-alanine under anaerobiosis. The enzyme reacted readily with sulfite to form a covalent reversible adduct and stabilized the red anionic form of the flavin semiquinone on photoreduction in the presence of 5-deazariboflavin; the 3,4-dihydro-FAD form was not detectable after reduction with sodium borohydride. Thus D-amino-acid oxidase from yeast exhibited most of the general properties of the dehydrogenase/oxidase class of flavoproteins; at the same time, the enzyme showed some peculiar features with respect to the same protein from pig kidney.
Pilone Simonetta
M
M
Department of General Physiology and Biochemistry, University of Milan, Italy.
Pollegioni
L
L
Casalin
P
P
Curti
B
B
Ronchi
S
S
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D003605:D-Amino-Acid Oxidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D004492:Edetic Acid / Q000494:pharmacology; D004586:Electrophoresis / Q000379:methods; D004789:Enzyme Activation / Q000187:drug effects; D005420:Flavoproteins / Q000032:analysis; D007668:Kidney / Q000201:enzymology; D010084:Oxidation-Reduction / Q000187:drug effects; D013053:Spectrophotometry; D013447:Sulfites / Q000494:pharmacology; D015003:Yeasts / Q000201:enzymology*
D000596:Amino Acids; D001565:Benzoates; D005420:Flavoproteins; D013447:Sulfites; D004492:Edetic Acid; D003605:D-Amino-Acid Oxidase