PURIFICATION AND PROPERTIES OF BRAIN ALKALINE PHOSPHATASE

Abstract

Abstract— Alkaline phosphatase from sheep brain has been purified to homogeneity. The method includes butanol extraction, fractional ethanol precipitation, ion‐exchange chromatography on DEAE‐cellulose, and on DEAE‐Sephadex followed by Sephadex G‐200 filtration. By these steps, the enzyme is purified 22,920‐fold with 15% recovery. The homogeneous enzyme is shown to be a sialoglycoprotein in nature. Neuraminidase treatment reduces the electrophoretic mobility of the enzyme. The enzyme shows pyridoxal phosphate phosphatase activity along with p ‐nitrophenylphosphate phosphatase activity. Both these compounds behave as mutual alternate competitive substrates. The general properties of the enzyme are described.