title: The oxidation product of molybdenum cofactor from milk xanthine oxidase.
abstract: In extracts of acid treated molybdenum cofactor containing xanthine oxidase, fluorescence is maximally developed upon a three hours incubation. Analysis by means of reversed phase HPLC revealed the presence of several fluorescent compounds, the main one being a blue fluorescent compound with an emission maximum of 465 nm when maximal excited at 395 nm at a neutral pH. Definite proof is presented that this compound is the oxidation product of the molybdenum cofactor. The remaining fluorescent products are shown to be pterin-derivatives, yielding predominantly pterin-6-carboxylic acid upon permanganate oxidation. Purified oxidation product of molybdenum cofactor however, didn's yield a fluorescent derivative at all upon treatment with permanganate.
authors.affiliation: Free University, Department of Microbiology, Amsterdam, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: van Spanning
authors.forename: C W
authors.initials: CW
authors.lastname: Wansell-Bettenhaussen
authors.forename: L F
authors.initials: LF
authors.lastname: Oltmann
authors.forename: A H
authors.initials: AH
authors.lastname: Stouthamer
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003067:Coenzymes; D008667:Metalloproteins / Q000032:analysis*; D008892:Milk / Q000201:enzymology*; D000090006:Molybdenum Cofactors; D010084:Oxidation-Reduction; D011621:Pteridines / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000032:analysis; D013997:Time Factors; D014969:Xanthine Oxidase / Q000032:analysis*
chemical_list: D003067:Coenzymes; D008667:Metalloproteins; D000090006:Molybdenum Cofactors; D011621:Pteridines; D013438:Sulfhydryl Compounds; D014969:Xanthine Oxidase; C022261:molybdopterin