title: Synthesis and application of isotopically labeled flavin nucleotides.
abstract: Flavin nucleotides, i.e. flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), are utilized as prosthetic groups and/or substrates by a myriad of proteins, ranging from metabolic enzymes to light receptors. Isotopically labeled flavins have served as invaluable tools in probing the structure and function of these flavoproteins. Here we present an enzymatic synthesis of several radio- and stable-isotope labeled flavin nucleotides from commercially available labeled riboflavin and ATP. The synthetic procedure employs a bifunctional enzyme, Corynebacterium ammoniagenes FAD synthetase, that sequentially converts riboflavin to FMN and then to FAD. The final flavin product (FMN or FAD) is controlled by the concentration of ATP in the reaction. Utility of the synthesized labeled FAD cofactors is demonstrated in flavin-dependent thymidylate synthase. The described synthetic approach can be easily applied to the production of flavin nucleotide analogues from riboflavin precursors.
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA, 52242-1727, United States.|Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, United States.
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Mishanina
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA, 52242-1727, United States.
authors.forename: Amnon
authors.initials: A
authors.lastname: Kohen
mesh_terms: D005486:Flavin Mononucleotide / Q000737:chemistry*; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D009713:Nucleotidyltransferases / Q000737:chemistry*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000302:isolation & purification*
chemical_list: D019275:Radiopharmaceuticals; D005182:Flavin-Adenine Dinucleotide; D005486:Flavin Mononucleotide; D009713:Nucleotidyltransferases; C020143:FMN adenylyltransferase
keywords: FAD synthetase; flavin adenine dinucleotide; isotopic labeling; thymidylate synthase