PHOSPHATASE STUDIES

Specificity studies on muscle phosphorylase phosphatase.

Zone electrophoretic studies of serum alkaline phosphatase.

Escherichia coli alkaline phosphatase. Kinetic studies with the tetrameric enzyme.

1. The stability of the tetrameric form of Escherichia coli alkaline phosphatase was examined by analytical ultracentrifugation. 2. The stopped-flow technique was used to study the hydrolysis of nitrophenyl phosphates by the alkaline phosphatase tetramer at pH7.5 and 8.3. In both cases transient product formation was observed before the steady state was attained. Both transients consisted of th...

Studies on biliary excretion of alkaline phosphatase in the rat.

Although the amount of alkaline phosphatase in the serum has been used as a clinical test for several decades, there is still controversy over the wvay in which the increased levels found in hepatobiliary diseases are reached. It has been generally believed that the increased enzyme activity in the serum commonly observed results from some combination of decreased excretion in the bile and, in ...

Kinetic studies of the inhibition of muscle phosphorylase phosphatase.

Inorganic phosphate, glucose l-phosphate, divalent metal ions, EDTA, m-propoxybenzamidine, and AMP were found to be competitive inhibitors of the reaction catalyzed by phosphorylase phosphatase. By a comparison of kinetic studies with the substrates, phosphorylase a and the phosphorylated peptide, it was deduced that inorganic phosphate affected the reaction by binding to the catalyst, whereas ...