Electrochemical assay of endo-depolymerase activity of cellulases

A method for determination of endo-1,4-beta -D-glucanase activity of cellul ase samples based on the indirect measurement of decrease in viscosity of a carboxymethylcellulose solution in an electrochemical cell in the presence of an electron carrier was developed. A rotating disk electrode is used as the working electrode. When two reactions (enzymatic and electrochemical) proceeded in the cell simultaneously, the limiting diffusion current at a c onstant applied potential increases as the viscosity of the solution decrea ses. Conditions where the initial rate of change of diffusion current (dI/d t) is proportional to the enzyme concentration were found. A good correlati on between the new method and a previously known viscometric method for det ermination of endoglucanase activity was observed.