Electrochemical Assay of Endo-depolymerase Activity of Cellulases

A. A. Skomarovsky^*, I. N. Zorov, S. G. Grishutin, A. V. Markov, A. P. Sinitsyn, A. V. Gusakov, A. D. Ryabov, and B. B. Gnedenko

School of Chemistry, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-0997; E-mail: askomarovsky@enzyme.chem.msu.ru

^* To whom correspondence should be addressed.

Received February 24, 2000; Revision received March 14, 2000

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A method for determination of endo-1,4-beta-D-glucanase activity of cellulase 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 constant applied potential increases as the viscosity of the solution decreases. Conditions where the initial rate of change of diffusion current (dI/dt) is proportional to the enzyme concentration were found. A good correlation between the new method and a previously known viscometric method for determination of endoglucanase activity was observed.

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KEY WORDS: hydrodynamic voltammetry, endo-depolymerase activity, rotating disc electrode, cellulases, viscosity

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