ASSESSMENT OF ENDO-1,4-BETA-D-GLUCANASE ACTIVITY BY A RAPID COLORIMETRIC ASSAY USING DISODIUM 2,2'-BICINCHONINATE

Abstract

It is widely accepted that viscometric assays are the most sensitive methods for evaluation of endoglucanase activities, because of the preferential attack of these enzymes on internal bonds of the substrate. However, due to the high sensitivity of the disodium 2,2′-bicinchoninate assay, we could measure, in a onestep method, the initial stages of the degradation of cellulose derivatives by endo-1,4-β-D-glucanases, by determining the reducing end-groups released. We report the applicability of the method for the determination of activity, and the K_m for the endoglucanase-I from Trichoderma reesei. This assay can be extended to the evaluation of reducing groups released by the action of many other carbohydrases, either with endo- or exo-type activity.