底物-辅因子比例对高温下部分纯化的无机焦磷酸酶活性的影响
INFLUENCE OF SUBSTRATE-COFACTOR RATIOS ON PARTIALLY PURIFIED INORGANIC PYROPHOSPHATASE ACTIVITY AT ELEVATED TEMPERATURES.
作者信息
MATHEMEIER P F, MORITA R Y
出版信息
J Bacteriol. 1964 Dec;88(6):1661-6. doi: 10.1128/jb.88.6.1661-1666.1964.
Mathemeier, Paul F. (Oregon State University, Corvallis), and Richard Y. Morita. Influence of substrate-cofactor ratios on partially purified inorganic pyrophosphatase activity at elevated temperatures. J. Bacteriol. 88:1661-1666. 1964.-Inorganic pyrophosphatase of Bacillus stearothermophilus was studied for optimal substrate-cofactor ratios at 60 to 100 C. Mg(++) was the primary cofactor, and Co(++) resulted in 50% enzyme activity at 60 C. The pH optima differed for the Mg(++) activated and Co(++) activated pyrophosphatase. At 80 C and above, Co(++) replaced Mg(++) as the optimal cofactor in the enzyme reaction. The optimal ratio of pyrophosphate to Mg(++) varied from 2 to 0.25, dependent on enzyme concentration. The optimal pyrophosphate-cobalt ratio was constant at 1.0. The enzyme catalyzed appreciable pyrophosphate hydrolysis at 95 C.
马瑟迈尔，保罗·F.（俄勒冈州立大学，科瓦利斯），以及理查德·Y. 森田。底物 - 辅因子比例对嗜热脂肪芽孢杆菌部分纯化的无机焦磷酸酶在高温下活性的影响。《细菌学杂志》88:1661 - 1666。1964年。——研究了嗜热脂肪芽孢杆菌的无机焦磷酸酶在60至100摄氏度下的最佳底物 - 辅因子比例。镁离子（Mg(++)）是主要的辅因子，钴离子（Co(++)）在60摄氏度时能使酶活性达到50%。镁离子激活的和钴离子激活的焦磷酸酶的最适pH值不同。在80摄氏度及以上，钴离子（Co(++)）取代镁离子（Mg(++)）成为酶反应中的最佳辅因子。焦磷酸与镁离子（Mg(++)）的最佳比例从2变化到0.25，取决于酶的浓度。焦磷酸 - 钴的最佳比例恒定为1.0。该酶在95摄氏度时能催化可观的焦磷酸水解。
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