The catalytic-centre activity and kinetic properties of bovine milk alkaline phosphatase.
1. The phosphorylation of milk alkaline phosphatase was studied under various conditions: maximum incorporation occurred at pH5.0 and 50% incorporation at pH6.6-7.0. 2. The phosphorylation was shown to be specific and the results suggest that the active centre of the enzyme is involved in the process. 3. Phosphoryl-enzyme is rapidly hydrolysed at alkaline pH. at pH7.0 the results suggest that a phosphoryl-enzyme could occur as a transient intermediate in the hydrolysis of phosphate esters by the phosphatase. 4. The catalytic-centre activity of the enzyme was found to be 2700sec.(-1) at pH10.0 and 25 degrees with p-nitrophenyl phosphate as substrate.
D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D002384:Catalysis; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D008892:Milk / Q000201:enzymology*; D009596:Nitrophenols; D010710:Phosphates; D013053:Spectrophotometry
D009596:Nitrophenols; D010710:Phosphates; D000469:Alkaline Phosphatase