title: Effect of pH on the modulation of rat osseous plate alkaline phosphatase by metal ions.
abstract: 1. Metal ions other than zinc and magnesium were effective in modulating the activity of rat osseous plate alkaline phosphatase. 2. Increasing pH had remarkable effects on the modulation of rat osseous plate alkaline phosphatase. 3. The modulation of enzyme activity by zinc, manganese and cobalt ions was slightly affected by pH variations. 4. Zinc ions were stimulatory for the enzyme at very low concentrations (50 nM). Above 50 nM zinc ions inhibited the enzyme by displacing magnesium ions. 5. Calcium ions were inhibitors of alkaline phosphatase (Kd = 10 microM) whereas manganese (Kd = 1.3 microM) and cobalt (Kd = 0.2 microM) ions were stimulatory in the pH range 8.0-10.0.
authors.affiliation: Departamento de Química, Faculdade de Filosofia Ciências e Letras, USP, Ribeirão Preto, Brazil.
authors.forename: F A
authors.initials: FA
authors.lastname: Leone
authors.forename: J M
authors.initials: JM
authors.lastname: Pizauro
authors.forename: P
authors.initials: P
authors.lastname: Ciancaglini
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D006132:Growth Plate / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008345:Manganese / Q000378:metabolism; D008670:Metals / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D015032:Zinc / Q000378:metabolism
chemical_list: D008670:Metals; D008345:Manganese; D000469:Alkaline Phosphatase; D008274:Magnesium; D015032:Zinc; D002118:Calcium