A Biochemical Comparison of Fungal GH6 Cellobiohydrolases.

A Biochemical Comparison of Fungal GH6 Cellobiohydrolases. Biochem J. 2019 Jul 16;: Authors: Christensen SJ, Krogh KBRM, Spodsberg N, Borch K, Westh P Abstract Cellobiohydrolases (CBHs) from Glycoside Hydrolase Family 6 (GH6) make up an important part of the secretome in many cellulolytic fungi. They are also of technical interest, particularly because they are part of the enzyme cocktails that are used for industrial breakdown of lignocellulosic biomass. Nevertheless, functional studies of GH6 CBHs are scarce and focused on a few model enzymes. To elucidate functional breadth among GH6 CBHs, we conducted a comparative biochemical study of seven GH6 CBHs originating from fungi living in different habitats, in addition to one enzyme variant. The enzyme sequences were investigated by phylogenetic analyses to ensure that they were not closely related phylogenetically. The selected enzymes were all heterologously expressed in Aspergillus oryzae , purified and thoroughly characterized biochemically. This approach allowed direct comparisons of functional data, and the results revealed substantial variability. For example, the adsorption capacity on cellulose spanned two orders of magnitude and kinetic parameters, derived from two independent steady-state methods also varied significantly. While the different functional parameters covered wide ranges, they were not independent since they changed in parallel between two poles. One pole was c...
Source: The Biochemical Journal - Category: Biochemistry Authors: Tags: Biochem J Source Type: research