Further characterization of alkaline phosphatases of human kidney and urine.

Human kidney alkaline phosphatase (AP) react with antisera to liver and intestinal AP. The respective kidney enzymes are designated as KLi and KI. Comparison with liver AP showed that KLi was salted out at the same ammonium sulfate concentration (66%) as the liver enzyme; KLi was antigenically identical with liver AP; the electrophoretic mobility of KLi was that of a gamma-globulin whereas liver AP was an alpha2-globulin. the liver enzyme was lighter (130,000 daltons) than KLi (150,000 daltons). KI and intestinal AP shared most properties: antigenically they were indistinguishable; both contained two components one of which was 80,000 daltons, the other was heavier (120,000 daltons for KI, 130,000 daltons for intestinal AP). Urinary AP consisted only of the lighter component (80,000 dalton). Methods for partial separation of the three kidney APs are given.