Engasser J M
Biochim Biophys Acta. 1978 Oct 12;526(2):301-10. doi: 10.1016/0005-2744(78)90122-5.
As the kinetic behavior of bound enzymes is frequently affected by substrate diffusion between the bulk solution and the catalytic sites, a fast and simple method is proposed to detect and, subsequently, to remove diffusion effects on measured enzymic activities. The procedure makes use of the effectiveness factor concept and essentially involves the direct determination on two diagrams of the magnitude of both external and internal diffusion limitations. It requires a prior estimation of the volume and external surface area of the matrix, of the substrate external transport coefficient and internal diffusivity, and of the intrinsic Michaelis constant of the bound enzyme. However, it does not necessitate the knowledge of the quantity of bound enzyme. The two basic graphs have been calculated for Michaelis-Menten kinetics. They can also be used to evaluate diffusional effects on two-substrate reactions, as illustrated with previously published data.
由于结合酶的动力学行为常常受到底物在本体溶液与催化位点之间扩散的影响，本文提出了一种快速简便的方法来检测并随后消除扩散对所测酶活性的影响。该方法利用有效因子概念，主要涉及在两张图上直接测定外部和内部扩散限制的大小。它需要事先估计基质的体积和外表面积、底物的外部传输系数和内部扩散率，以及结合酶的固有米氏常数。然而，它并不需要知道结合酶的量。针对米氏动力学计算了两张基本图表。正如先前发表的数据所示，它们也可用于评估扩散对双底物反应的影响。
