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Cloning, Purification, and Characterization of Galactomannan-Degrading Enzymes from Myceliophthora thermophila

G. S. Dotsenko1,2*, M. V. Semenova2, O. A. Sinitsyna1,2, S. W. A. Hinz3, J. Wery3, I. N. Zorov1,2, E. G. Kondratieva2, and A. P. Sinitsyn1,2

1Chemical Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia; fax: (495) 932-8846; E-mail: info@rector.msu.ru; gsdotsenko@gmail.com

2Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33/2, 119071 Moscow, Russia; fax: (495) 954-2732; E-mail: inbi@inbi.ras.ru

3Dyadic Nederland BV, Nieuwe Kanaal 7s, 6709 PA, Wageningen, The Netherlands

* To whom correspondence should be addressed.

Received April 25, 2012; Revision received May 18, 2012
Genes of β-mannosidase 97 kDa, GH family 2 (bMann9), β-mannanase 48 kDa, GH family 5 (bMan2), and α-galactosidase 60 kDa, GH family 27 (aGal1) encoding galactomannan-degrading glycoside hydrolases of Myceliophthora thermophila C1 were successfully cloned, and the recombinant enzymes were purified to homogeneity and characterized. bMann9 displays only exo-mannosidase activity, the Km and kcat values are 0.4 mM and 15 sec–1 for p-nitrophenyl-β-D-mannopyranoside, and the optimal pH and temperature are 5.3 and 40°C, respectively. bMann2 is active towards galactomannans (GM) of various structures. The Km and kcat values are 1.3 mg/ml and 67 sec–1 for GM carob, and the optimal pH and temperature are 5.2 and 69°C, respectively. aGal1 is active towards p-nitrophenyl-α-D-galactopyranoside (PNPG) as well as GM of various structures. The Km and kcat values are 0.08 mM and 35 sec–1 for PNPG, and the optimal pH and temperature are 5.0 and 60°C, respectively.
KEY WORDS: Myceliophthora thermophila, β-mannosidase, β-mannanase, α-galactosidase, enzymatic hydrolysis

DOI: 10.1134/S0006297912110090