title: Characterization of acid and alkaline phosphatase activity in preparations of tubulin and microtubule-associated proteins.
abstract: Acid and alkaline phosphatase activity, determined by the hydrolysis of p-nitrophenyl phosphate, was found in preparations of microtubules purified from bovine brain by temperature-dependent assembly-disassembly and ion-exchange chromatography. Phosphocellulose-purified tubulin contained an associated acid phosphatase activity, stimulated by Mg2+ and by Zn2+. Alkaline phosphatase activity with a pH optimum of 10.4 was measured in a fraction of microtubule-associated proteins (MAPs). Kinetics and the effects of sodium fluoride, sodium tartrate, sulfhydryl-blocking agents, EDTA and Zn2+ are reported.
mesh_terms: D000135:Acid Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D008278:Magnesium Sulfate / Q000494:pharmacology; D008869:Microtubule-Associated Proteins; D008870:Microtubules / Q000201:enzymology*; D011506:Proteins / Q000378:metabolism*; D013431:Sulfates / Q000494:pharmacology; D014404:Tubulin / Q000302:isolation & purification / Q000378:metabolism*; D015032:Zinc / Q000494:pharmacology; D019287:Zinc Sulfate
chemical_list: D008869:Microtubule-Associated Proteins; D011506:Proteins; D013431:Sulfates; D014404:Tubulin; D008278:Magnesium Sulfate; D019287:Zinc Sulfate; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D015032:Zinc