Eisenthal Robert, Danson Michael J, Hough David W
Department of Biology & Biochemistry, University of Bath, Bath, UK.
Trends Biotechnol. 2007 Jun;25(6):247-9. doi: 10.1016/j.tibtech.2007.03.010. Epub 2007 Apr 12.
The ratio k(cat)/K(M)--often referred to as the "specificity constant"--is a useful index for comparing the relative rates of an enzyme acting on alternative, competing substrates. However, an alternative description, "catalytic efficiency", is frequently used, and on occasions misused, to compare the reactivity of two enzymes acting on the same substrate. Here, we highlight the pitfalls in using k(cat)/K(M) to compare the catalytic effectiveness of enzymes.
k(cat)/K(M)比值——常被称为“特异性常数”——是用于比较一种酶作用于不同竞争性底物时相对速率的有用指标。然而，“催化效率”这一替代描述经常被用来比较两种作用于同一底物的酶的反应活性，且有时会被误用。在此，我们强调使用k(cat)/K(M)来比较酶的催化效力时存在的陷阱。
