Comparative Analysis of the Properties of Recombinant Endo-1,4-β-Glucanase II and Its Chimeric Form with a Cellular Binding Module

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A chimeric form of Penicillium verruculosum endo-1,4-β-glucanase II (EGII), the C-terminus of which contains a cellulose-binding module (CBM) of P. verruculosum cellobiohydrolase I, is produced by the genetic engineering method. In the native form, the eglI gene does not have a region encoding CBM. The resulting chimeric enzyme is isolated in a homogeneous form and its properties are studied. The addition of CBM to EGII led to a significant increase in the activity of the chimeric enzyme relative to microcrystalline cellulose (MCC) and the appearance of its adsorption capacity in relation to cellulose. However, the addition of CBM to EGII led to a decrease in activity towards soluble polysaccharide substrates (carboxymethylcellulose and β-glucan). The chimeric form of the enzyme in the composition of the cellulase complex allowed us to hydrolyze cellulose-containing substrates more effectively. The yield of reducing sugars (RS) in the case of MCC hydrolysis after 24 h with a cellulose complex containing cellobiohydrolase I, β-glucosidase, and EGII-CBM in comparison with a complex containing EGII without CBM increased by 22%, while for chopped aspen wood the RS increased by 42%.