Properties of alkaline phosphatases from cellular cementum of rat molars.
The characteristics of nonspecific alkaline phosphatase, (APase, EC 3.1.3.1.) measured as beta-glycerophosphatase (GPase, EC 3.1.3.1.), inorganic pyrophosphatase (PPiase, EC 3.6.1.1.) and adenosine triphosphatase (ATPase, EC 3.6.1.3.) were studied in detail of butanol extracts prepared from rat molar cementum. Mg2+ was not absolutely essential to any of the activities, but at low levels was stimulatory in all cases. Higher concentrations were inhibitory. Ca2+ stimulated ATPase activity weakly at low levels, but was slightly inhibitory to the other enzyme activities. All enzyme activities showed nearly identical sensitivities to heat inactivation and to L-p-bromotetramisole and levamisole, which caused nearly complete inhibition. About 10-15% of the ATPase activity was insensitive to L-p-bromotetramisole and levamisole. The data are consistent with the concept that GPase, PPiase and ATPase activities of cementum to a major part stem from one enzyme, namely nonspecific alkaline phosphatase.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D003739:Dental Cementum / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D008963:Molar / Q000201:enzymology; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011755:Pyrophosphatases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D000469:Alkaline Phosphatase; C020674:glycerol-2-phosphatase; D010744:Phosphoric Monoester Hydrolases; D000251:Adenosine Triphosphatases; D011755:Pyrophosphatases