The metabolism of hypoxanthine desoxyriboside in animal tissues.

Klein (1) has made a detailed investigation of the action of “purine nucleosidase” on the various purine desoxyribosides. He found that preparations of animal tissues which split purine ribosides also split the purine desoxyribosides, yielding the purine base and a reducing sugar. The enzyme preparations were inactivated upon dialysis, but could be reactivated by the addition of arsenate or phosphate. Kalckar (2) studied this enzyme, and found that “purine nucleosidase” was in reality a purine nucleoside phosphorylase. The reaction catalyzed by this enzyme was