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Hokkaido University Collection of Scholarly and Academic Papers >
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Multifunctional cellulase catalysis targeted by fusion to different carbohydrate-binding modules
This item is licensed under:Creative Commons Attribution 4.0 International
| Title: | Multifunctional cellulase catalysis targeted by fusion to different carbohydrate-binding modules |
| Authors: | Walker, Johnnie A. Browse this author | | Takasuka, Taichi E. Browse this author | | Deng, Kai Browse this author | | Bianchetti, Christopher M. Browse this author | | Udell, Hannah S. Browse this author | | Prom, Ben M. Browse this author | | Kim, Hyunkee Browse this author | | Adams, Paul D. Browse this author | | Northen, Trent R. Browse this author | | Fox, Brian G. Browse this author |
| Keywords: | Cellulase | | Xylanase | | Hemicellulase | | Mannanase | | Carbohydrate binding module | | Ruminoclostridium thermocellum | | Enzyme engineering | | Biofuels | | Mass spectrometry | | Kinetic analysis |
| Issue Date: | 2015 |
| Publisher: | BioMed Central |
| Journal Title: | Biotechnology for Biofuels |
| Volume: | 8 |
| Start Page: | 220 |
| Publisher DOI: | 10.1186/s13068-015-0402-0 |
| Abstract: | Background:Carbohydrate binding modules (CBMs) bind polysaccharides and help target glycoside hydrolases catalytic domains to their appropriate carbohydrate substrates. To better understand how CBMs can improve cellulolytic enzyme reactivity, representatives from each of the 18 families of CBM found in Ruminoclostridium thermocellum were fused to the multifunctional GH5 catalytic domain of CelE (Cthe_0797, CelEcc), which can hydrolyze numerous types of polysaccharides including cellulose, mannan, and xylan. Since CelE is a cellulosomal enzyme, none of these fusions to a CBM previously existed. Results:CelEcc_CBM fusions were assayed for their ability to hydrolyze cellulose, lichenan, xylan, and mannan. Several CelEcc_CBM fusions showed enhanced hydrolytic activity with different substrates relative to the fusion to CBM3a from the cellulosome scaffoldin, which has high affinity for binding to crystalline cellulose. Additional binding studies and quantitative catalysis studies using nanostructure-initiator mass spectrometry (NIMS) were carried out with the CBM3a, CBM6, CBM30, and CBM44 fusion enzymes. In general, and consistent with observations of others, enhanced enzyme reactivity was correlated with moderate binding affinity of the CBM. Numerical analysis of reaction time courses showed that CelEcc_CBM44, a combination of a multifunctional enzyme domain with a CBM having broad binding specificity, gave the fastest rates for hydrolysis of both the hexose and pentose fractions of ionic-liquid pretreated switchgrass. Conclusion:We have shown that fusions of different CBMs to a single multifunctional GH5 catalytic domain can increase its rate of reaction with different pure polysaccharides and with pretreated biomass. This fusion approach, incorporating domains with broad specificity for binding and catalysis, provides a new avenue to improve reactivity of simple combinations of enzymes within the complexity of plant biomass. |
| Rights: | © 2015 Walker et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. | | https://creativecommons.org/licenses/by/4.0/legalcode |
| Type: | article |
| URI: | http://hdl.handle.net/2115/68237 |
| Appears in Collections: | 農学院・農学研究院 (Graduate School of Agriculture / Faculty of Agriculture) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 高須賀 太一
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