Zn(II)-113Cd(II) and Zn(II)-Mg(II) hybrids of alkaline phosphatase. 31P and 113Cd NMR.
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منابع مشابه
Alkaline phosphatase. 31P NMR probes of the mechanism.
31P NMR signals from substrates and products of alkaline phosphatase have been adapted to measure the rates and product ratios for the hydrolysis and phosphotransferase reactions from pH 6 to 10. Below pH 8, glycerol is a poorer acceptor than H2O (glycerol phosphates:Pi = 0.5). Tris is a more effective acceptor below pH 8, showing a maximum acceptor efficiency at pH 8 (Tris phosphate:Pi = 2). P...
متن کاملAllosteric interactions between metal ion and phosphate at the active sites of alkaline phosphatase as determined by 31P NMR and 113Cd NMR.
““Cd and :“P NMR have been used to determine the effect of variations in the nature and stoichiometry of bound metal ion and pH on the allosteric interactions (negative cooperativity) induced on association of phosphate with the dimeric zinc metalloenzyme Escherichia coli alkaline phosphatase. At pH 8.0, successive additions of an extra two Zn’+ ions and one Mg”+ ion to the Znzs+ enzyme result ...
متن کامل31P NMR of alkaline phosphatase. Dependence of phosphate binding stoichiometry on metal ion content.
Alkaline phosphatase of Escherichia coli (a dimeric zinc metalloenzyme of identical subunits) containing either 2 catalytic Zn(II) ions or 2 catalytic Cd(I1) ions shows absolute negative cooperativity of phosphate binding as determined by 31P NMR of enzyme-bound phosphate species. With excess phosphate at millimolar concentrations, only 1 mol of noncovalent phosphate complex, E.P (31P resonance...
متن کامل31P nuclear magnetic resonance of phosphoenzyme intermediates of alkaline phosphatase.
Covalent (E-P) and noncovalent (E X P) phosphoenzyme intermediates exist on the reaction path of alkaline phosphatase of Escherichia coli. Zn(II) and Cd(II) alkaline phosphatases both form E-P and E X P from inorganic phosphate. These intermediates show well separated 31P NMR resonances in slow chemical exchange with respect to each other and to unbound phosphate. The 31P signals of E X P of al...
متن کاملAllosteric Interactions between Metal Ion and Phosphate at the Active Sites of Alkaline Phosphatase as Determined by 31P NMR and l13Cd NMR*
““Cd and :“P NMR have been used to determine the effect of variations in the nature and stoichiometry of bound metal ion and pH on the allosteric interactions (negative cooperativity) induced on association of phosphate with the dimeric zinc metalloenzyme Escherichia coli alkaline phosphatase. At pH 8.0, successive additions of an extra two Zn’+ ions and one Mg”+ ion to the Znzs+ enzyme result ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1984
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)42944-9