Janssen A E, Vaidya A M, Halling P J
Department of Bioscience and Biotechnology, University of Strathclyde, Glasgow, United Kingdom.
Enzyme Microb Technol. 1996 Apr;18(5):340-6. doi: 10.1016/0141-0229(95)00075-5.
The fatty acid specificity of lipase from Candida rugosa during the esterification of saturated fatty acids and sulcatol in toluene has been studied. The true kinetic parameters are obtained by fitting the experimental data to a Ping-Pong kinetic model that includes alcohol inhibition. The fitted parameter values are compared with apparent values that would be obtained from restricted data sets in which one of the substrate concentrations was kept constant. It has been found that in reactions inhibited by alcohol the true Ping-Pong parameters can be significantly different from the apparent ones. Corrections for solvation are made by using activities instead of concentrations to fit the kinetic parameters. Though activity coefficients, estimated using the UNIFAC group contribution method, vary by over 25% for changing concentrations in the same solvent, their use did not improve the fit to the data. This contrasts with what has been found in comparisons of different solvents, where the differences in activity coefficients are much larger.
研究了皱褶假丝酵母脂肪酶在甲苯中饱和脂肪酸与紫苏醇酯化反应过程中的脂肪酸特异性。通过将实验数据拟合到包含醇抑制的乒乓动力学模型来获得真实的动力学参数。将拟合的参数值与从其中一种底物浓度保持恒定的受限数据集获得的表观值进行比较。已发现，在受醇抑制的反应中，真实的乒乓参数可能与表观参数有显著差异。通过使用活度而非浓度来拟合动力学参数，对溶剂化进行校正。尽管使用UNIFAC基团贡献法估算的活度系数在同一溶剂中随浓度变化超过25%，但使用它们并未改善对数据的拟合。这与在不同溶剂比较中发现的情况形成对比，在不同溶剂比较中，活度系数的差异要大得多。
