ALKALINE-PHOSPHATASE OF HIGH AND LOW-MOLECULAR MASS IN HUMAN-SERUM AND BILE - A COMPARATIVE-STUDY OF KINETIC-PROPERTIES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 26  (3) , 451-456
Abstract
The kinetic properties of high- and low-molecular-mass forms of alkaline phosphatase purified from serum and bile are studied to clarify their interrelationships. They share virtually identical kinetic properties, and obey the same general kinetics as the liver-derived isoenzyme from serum and the low-molecular-mass isoenzyme from bile with regard to optimum conditions of assay, activation by Mg ions, inhibition by L-homoarginine, inhibition by Ni and Zn ions and inactivation by urea. Most of the characteristics such as Km (at low Mg ion concentrations), Ki for L-homoarginine and half-life for urea inactivation, were closely similar for low- and high-molecular-mass alkaline phosphatase. These forms of alkaline phosphatase in plasma and bile are closely related. The possible nature of this relationship is discussed.