title: The reaction of 8-mercaptoflavins and flavoproteins with sulfite. Evidence for the role of an active site arginine in D-amino acid oxidase.
abstract: This work presents strong evidence that the role of the active site arginine in D-amino acid oxidase is to act as a positively charged group interacting with the flavin N(1)-C(2) = 0 locus. Modification with cyclohexanedione, which has been shown previously to modify specifically an active site arginine in D-amino acid oxidase (Ferti, C., Curti, B., Simonetta, M. P., Ronchi, S., Galliano, M., and Minchiotti, L. (1981) Eur. J. Biochem. 119, 553-557) destroys the ability of D-amino acid oxidase to stabilize the benzoquinoid type spectrum of 8-mercapto-FAD and destroys the ability to form a flavin N-5 adduct with sulfite. Both of these properties have been attributed to the presence of such a group. The active site lysine, histidine, and tyrosine have been ruled out as possibilities for such a group. In addition, the reactivity of flavoproteins containing 8-mercaptoflavin with sulfite has been examined and falls into the same two general classes as the reactivity of the native flavoproteins: oxidases form N-5 adducts while all of the other 8-mercaptoflavoproteins examined do not, forming instead the 8-sulfonate flavin.
mesh_terms: D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001665:Binding Sites; D003512:Cyclohexanones / Q000494:pharmacology; D003605:D-Amino-Acid Oxidase / Q000378:metabolism*; D004139:Dinitrofluorobenzene / Q000494:pharmacology; D005415:Flavins / Q000378:metabolism*; D005420:Flavoproteins / Q000378:metabolism*; D013053:Spectrophotometry; D013447:Sulfites / Q000378:metabolism*; D013552:Swine
chemical_list: C021217:8-mercaptoflavins; D003512:Cyclohexanones; D005415:Flavins; D005420:Flavoproteins; D013447:Sulfites; D001120:Arginine; D004139:Dinitrofluorobenzene; D003605:D-Amino-Acid Oxidase