Contribution of water to free energy of hydrolysis of pyrophosphate.
作者： Leopoldo De Meis , Maria Isabel Behrens , Jorge H. Petretski , Mario J. Politi
DOI: 10.1021/BI00347A042
关键词:
摘要: The energy of hydrolysis phosphate compounds varies depending on whether they are in solution or bound to the catalytic site enzymes. With purpose simulating conditions at site, observed equilibrium constant for pyrophosphate (Kobsd) was measured aqueous mixtures dimethyl sulfoxide, ethylene glycol, polymers glycol. reaction catalyzed by yeast inorganic pyrophosphatase 30 degrees C. All cosolvents used promoted a decrease Kobsd. Polymers glycol were more effective than sulfoxide decreasing higher molecular weight polymer, lower value A Kobsd from 346 M (delta G degree obsd = -3.5 kcal mol-1) 0.1 1.3 after addition 50% (w/v) poly(ethylene glycol) 8000 containing 0.9 mM MgCl2 and 1 Pi pH 8.0. association constants H+ Mg2+ presence different concentrations order calculate Keq ionic species pyrophosphate. all observed. results interpreted according concept that depends solvation energies reactants products.
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sci-hub.se 参考文章(48)
F J Kayne, M Cohn, B D Nageswara Rao, 31P NMR studies of enzyme-bound substrates of rabbit muscle pyruvate kinase. Equilibrium constants, exchange rates, and NMR parameters. Journal of Biological Chemistry. ,vol. 254, pp. 2689- 2696 ,(1979) , 10.1016/S0021-9258(17)30127-8
K. Ueberreiter, Change of water structure by solvents and polymers Colloid and Polymer Science. ,vol. 260, pp. 37- 45 ,(1982) , 10.1007/BF01447674
RICHARD L. CROSS, David CUNNINGHAM, JAMES K. TAMURA, Binding Change Mechanism for ATP Synthesis by Oxidative Phosphorylation and Photophosphorylation Current Topics in Cellular Regulation. ,vol. 24, pp. 335- 344 ,(1984) , 10.1016/B978-0-12-152824-9.50036-8
L de Meis, A de Souza Otero, O B Martins, E W Alves, G Inesi, R Nakamoto, Phosphorylation of sarcoplasmic reticulum ATPase by orthophosphate in the absence of Ca2+ gradient. Contribution of water activity to the enthalpy and the entropy changes. Journal of Biological Chemistry. ,vol. 257, pp. 4993- 4998 ,(1982) , 10.1016/S0021-9258(18)34623-4
Barry S. Cooperman, [28] The mechanism of action of yeast inorganic pyrophosphatase Methods in Enzymology. ,vol. 87, pp. 526- 548 ,(1982) , 10.1016/S0076-6879(82)87030-4
K Taniguchi, RL Post, Synthesis of adenosine triphosphate and exchange between inorganic phosphate and adenosine triphosphate in sodium and potassium ion transport adenosine triphosphatase. Journal of Biological Chemistry. ,vol. 250, pp. 3010- 3018 ,(1975) , 10.1016/S0021-9258(19)41587-1
L. de Meis, G. Inesi, ATP synthesis by sarcoplasmic reticulum ATPase following Ca2+, PH, temperature, and water activity jumps. Journal of Biological Chemistry. ,vol. 257, pp. 1289- 1294 ,(1982) , 10.1016/S0021-9258(19)68189-5
Kim H. Tan, Rex Lovrien, Enzymology in Aqueous-Organic Cosolvent Binary Mixtures Journal of Biological Chemistry. ,vol. 247, pp. 3278- 3285 ,(1972) , 10.1016/S0021-9258(19)45242-3
M Cohn, B D Rao, R K Scopes, 31P NMR study of bound reactants and products of yeast 3-phosphoglycerate kinase at equilibrium and the effect of sulfate ion. Journal of Biological Chemistry. ,vol. 253, pp. 8056- 8060 ,(1978) , 10.1016/S0021-9258(17)34360-0
L de Meis, Pyrophosphate of high and low energy. Contributions of pH, Ca2+, Mg2+, and water to free energy of hydrolysis Journal of Biological Chemistry. ,vol. 259, pp. 6090- 6097 ,(1984) , 10.1016/S0021-9258(20)82109-7