Сarbohydrate binding module CBM28 of endoglucanase Cel5D from Caldicellulosiruptor bescii recognizes crystalline cellulose.

Autor: Dvortsov IA; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia. Electronic address: dvortsov@img.ras.ru., Lunina NA; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia., Chekanovskaya LA; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia., Gromov AV; Gamaleya Research Institute of Epidemiology and Microbiology, Russian Ministry of Healthcare, 123098 Moscow, Russia., Schwarz WH; Institute for Microbiology, Technische Universität München, D-85350 Freising-Weihenstephan, Germany., Zverlov VV; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia; Institute for Microbiology, Technische Universität München, D-85350 Freising-Weihenstephan, Germany., Velikodvorskaya GA; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia., Demidyuk IV; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia., Kostrov SV; Institute of Molecular Genetics, Russian Academy of Sciences, 123182 Moscow, Russia.
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2018 Feb; Vol. 107 (Pt A), pp. 305-311. Date of Electronic Publication: 2017 Sep 06.
DOI: 10.1016/j.ijbiomac.2017.08.165
Abstrakt: Optimal catalytic activity of endoglucanase Cel5D from the thermophilic anaerobic bacterium Caldicellulosiruptor bescii requires the presence of a carbohydrate-binding module of family 28, CbCBM28. The binding properties of CbСВМ28 with cello-, laminari-, xylo- and chito-oligosaccharides were studied by isothermal titration calorimetry. CbСВМ28 bound only cello-oligosaccharides comprising at least four glucose residues with binding constants of 2.5·10 4 and 2.2·10 6 M -1 for cellotetraose and cellohexaose, respectively. The interaction between CbСВМ28 and amorphous cellulose is best described by a two-binding-site model with the binding constants of 1.5·10 5 and 1.9·10 5 M -1 . In a competitive binding assay in the presence of a 10-fold excess of cellohexaose the binding constant of CbСВМ28 to amorphous cellulose was 1.9·10 5 M -1 . A two-binding-site model also better approximates the binding to Avicel with the binding constants of 8.3·10 5 and 3.2·10 4 M -1 ; while in the presence of cellohexaose, the binding is described by a single-binding-site model with the binding constant of 2.3·10 4 M -1 . With CbСВМ28 binding to bacterial crystalline cellulose with a constant of 7.4·10 4 M -1 , this is the first report of such a strong binding to crystalline cellulose for a module of family 28.
(Copyright © 2017 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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