Isolation of Crystalline Quinolinate Phosphoribosyltransferase from Alcaligenes eutrophus nov. subsp. quinolinicus and Its Behavior on Polyacrylamide Gel Disc Electrophoresis

Abstract

Quinolinate phosphoribosyltransferase (EC 2.4.2.19) was purified and crystallized from cell-free extracts of Alcaligenes eutrophus nov. subsp. quinolinicus, IAM 12305 which was isolated in our laboratory from soil. The enzyme was labile in the cold, and all purification steps were performed at room temperature (10_??_15°C). The crystalline enzyme was certified to be homogeneous by ultracentrifugal analysis and starch-gel electrophoresis. On poly-acrylamide gel disc electrophoresis, the crystalline enzyme showed a multiple profile, but it showed a single band by addition of a certain amount of glycerol and 2-mercaptoethanol. The adding effect of these compounds was discussed.