title: Synthesis and characterization of 3H-labelled tetrahydrobiopterin.
abstract: We synthesized [3'-3H]-5,6,7,8-tetrahydrobiopterin from [8,5'-3H]guanosine 5'-triphosphate ([8,5'-3H]GTP) using GTP cyclohydrolase (EC 3.5.4.16), 6-pyruvoyltetrahydropterin synthase and sepiapterin reductase (EC 1.1.1.153). After purification by cation-exchange h.p.l.c. a solution of radiochemically pure (> 95%) [3'-3H]-5,6,7,8-tetrahydrobiopterin with a specific activity of 9.2 Ci/mmol was obtained. The product proved well suited for studying the binding of tetrahydrobiopterin to nitric-oxide synthase.
authors.affiliation: Institut für Medizinische Chemie und Biochemie, Universität Innsbruck, Austria.
authors.forename: E R
authors.initials: ER
authors.lastname: Werner
authors.forename: M
authors.initials: M
authors.lastname: Schmid
authors.forename: G
authors.initials: G
authors.lastname: Werner-Felmayer
authors.forename: B
authors.initials: B
authors.lastname: Mayer
authors.forename: H
authors.initials: H
authors.lastname: Wachter
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D001708:Biopterins / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D019001:Nitric Oxide Synthase; D011485:Protein Binding; D011869:Radioligand Assay; D014316:Tritium
chemical_list: D014316:Tritium; D001708:Biopterins; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; C003402:sapropterin