Fig. 2.
Purification and characterization of the D→O protein factor in Fraction L. (A) The steps of purification strategy starting with bovine milk are depicted as a flow-chart. Fractions containing D→O activity are shaded in orange. Detailed conditions and chromatograms for anion exchange, cation exchange, and hydroxyapatite were described in SupplementaryFigure S1 (Supplementary material, Section 1). Result of gel filtration chromatography was indicated in Fig. 3A. (B) Characterization of bovine milk D→O activity. Exogenous purified XDH was incubated with the bovine milk Fractions. 1, Fraction II; 2, mixture of Fractions L and S; 3, Fraction L; 4, Fraction S; 5, heat denatured Fraction II; 6, mixture of Fraction L and heat denatured Fraction S; 7, mixture of heat denatured Fraction L and Fraction S. Converted XO activity was indicated as O2-dependent urate formation (nmol/min). (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)