Klesov A A, Grigorash S Iu
Biokhimiia. 1981 Jan;46(1):110-9.
It was shown that the kinetics of multienzyme cellulase complexes are generally characterized by the absence of any single rate-limiting step of hydrolysis, even when the rates of individual steps of the process are substantially different. This peculiarity of the kinetic behaviour of cellulases can be explained in terms of certain "shunt ways" in a series of individual steps of enzymatic degradation of cellulose into glucose. A basic kinetic scheme for the degradation of cellulose was developed and proved experimentally for hydrolysis of milled cotton linters under the action of ten various cellulase complexes from the fungi Trichoderma, Geotrichum and Aspergillus. It was found that the value of the stationary rate of glucose formation in all cases is determined by the effect of two or three cellulolytic components of the complexes. It was concluded that the mechanism of native cellulose hydrolysis is the same for all cellulase complexes under study irrespective of their composition and origin.
结果表明，多酶纤维素酶复合物的动力学通常表现为不存在任何单一的水解限速步骤，即使该过程中各个步骤的速率存在显著差异。纤维素酶这种独特的动力学行为可以通过纤维素酶促降解为葡萄糖的一系列单独步骤中的某些“旁路途径”来解释。我们制定了纤维素降解的基本动力学方案，并通过实验证明了在木霉、地霉和曲霉这三种真菌的十种不同纤维素酶复合物作用下，研磨棉短绒的水解情况。结果发现，在所有情况下，葡萄糖生成的稳定速率值由复合物中两到三种纤维素分解成分的作用决定。得出的结论是，在所研究的所有纤维素酶复合物中，天然纤维素水解的机制是相同的，无论其组成和来源如何。
