Properties of Enzyme Preparations and Homogeneous Enzymes – Endoglucanases EG2 Penicillium verruculosum and LAM Myceliophthora thermophila

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D. A. Merzlov^1*, I. N. Zorov^1,2, G. S. Dotsenko², Yu. A. Denisenko², A. M. Rozhkova², A. D. Satrutdinov², E. A. Rubtsova², E. G. Kondratieva², and A. P. Sinitsyn^1,2

¹Chemical Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia; fax: +7 (495) 932-8846; E-mail: dmitriymerzlov@gmail.com

²Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia; fax: +7 (495) 954-2732; E-mail: inbi@inbi.ras.ru

^* To whom correspondence should be addressed.

Received November 25, 2014; Revision received December 30, 2014

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The genes of endoglucanases EG2 (36.2 kDa) Penicillium verruculosum and LAM (30.8 kDa) Myceliophthora thermophila were cloned in P. verruculosum recombinant strain. New enzyme preparations with highly stable activity against β-glucan and laminarin were obtained and investigated, homogeneous enzymes EG2 (EC 3.2.1.4) and LAM (EC 3.2.1.6) being purified and characterized. For β-glucan, the EG2 K_m value was found to be 10 times higher than that for LAM; however, EG2 demonstrated greater processivity due to its higher k_cat. The pH and temperature optima of EG2 and LAM activity against barley β-glucan overlapped and were 4.3-4.9 and 61-67°C, respectively, and EG2 appeared to be more stable than LAM. Oligosaccharides with degree of polymerization 2-10 were formed by hydrolysis of β-glucan and laminarin by the studied enzymes. The recombinant enzyme preparations were faster and more effective in decreasing the reduced viscosity of wholegrain barley extract than some commercial enzyme preparations. Thus, the new enzyme preparations seem to be rather perspective as feed additives for degradation of non-starch polysaccharides in grain animal feed.

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KEY WORDS: endoglucanase, β-glucan, β-glucan endodepolymerases, enzyme preparations, Penicillium verruculosum, Myceliophthora thermophila

DOI: 10.1134/S0006297915040112

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