Cercignani G
Department of Physiology and Biochemistry, University of Pisa, Italy.
Anal Biochem. 1987 Nov 1;166(2):418-23. doi: 10.1016/0003-2697(87)90593-8.
Optimal monitor wavelengths and differential millimolar extinction coefficients (m delta epsilon) for rate determination of reactions catalyzed by adenosine deaminases on several substrates have been investigated as a function of pH in the range from 6.5 to 12. The values found are in some cases at variance with those quoted in the biochemical literature. The effect of pH on m delta epsilon values is shown to be clearly related to acid-base properties of product and/or substrate in the reaction. Experimental data are in most cases used to derive analytical functions describing the pH dependence of m delta epsilon. For the conversion of adenosine to inosine at pH 6.5, the following values of m delta epsilon +/- SE were obtained: at 263 nm, 8.27 +/- 0.02; at 264 nm, 8.36 +/- 0.02; at 265 nm, 8.27 +/- 0.03. These represent absolute maximal values as a function of pH.
已研究了用于测定腺苷脱氨酶催化的几种底物反应速率的最佳监测波长和微分毫摩尔消光系数（mδε），其作为pH在6.5至12范围内的函数。所发现的值在某些情况下与生化文献中引用的值不同。结果表明，pH对mδε值的影响与反应中产物和/或底物的酸碱性质明显相关。在大多数情况下，实验数据用于推导描述mδε对pH依赖性的分析函数。对于在pH 6.5下腺苷转化为肌苷的反应，获得了以下mδε±SE值：在263nm处，8.27±0.02；在264nm处，8.36±0.02；在265nm处，8.27±0.03。这些代表了作为pH函数的绝对最大值。
