The impact of the carbohydrate-binding module on how a lytic polysaccharide monooxygenase modifies cellulose fibers
Loading...
Access rights
openAccess
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Date
2024-08-24
Department
Major/Subject
Mcode
Degree programme
Language
en
Pages
16
Series
Biotechnology for Biofuels and Bioproducts, Volume 17, issue 1
Abstract
Background: In recent years, lytic polysaccharide monooxygenases (LPMOs) that oxidatively cleave cellulose have gained increasing attention in cellulose fiber modification. LPMOs are relatively small copper-dependent redox enzymes that occur as single domain proteins but may also contain an appended carbohydrate-binding module (CBM). Previous studies have indicated that the CBM “immobilizes” the LPMO on the substrate and thus leads to more localized oxidation of the fiber surface. Still, our understanding of how LPMOs and their CBMs modify cellulose fibers remains limited. Results: Here, we studied the impact of the CBM on the fiber-modifying properties of NcAA9C, a two-domain family AA9 LPMO from Neurospora crassa, using both biochemical methods as well as newly developed multistep fiber dissolution methods that allow mapping LPMO action across the fiber, from the fiber surface to the fiber core. The presence of the CBM in NcAA9C improved binding towards amorphous (PASC), natural (Cell I), and alkali-treated (Cell II) cellulose, and the CBM was essential for significant binding of the non-reduced LPMO to Cell I and Cell II. Substrate binding of the catalytic domain was promoted by reduction, allowing the truncated CBM-free NcAA9C to degrade Cell I and Cell II, albeit less efficiently and with more autocatalytic enzyme degradation compared to the full-length enzyme. The sequential dissolution analyses showed that cuts by the CBM-free enzyme are more evenly spread through the fiber compared to the CBM-containing full-length enzyme and showed that the truncated enzyme can penetrate deeper into the fiber, thus giving relatively more oxidation and cleavage in the fiber core. Conclusions: These results demonstrate the capability of LPMOs to modify cellulose fibers from surface to core and reveal how variation in enzyme modularity can be used to generate varying cellulose-based materials. While the implications of these findings for LPMO-based cellulose fiber engineering remain to be explored, it is clear that the presence of a CBM is an important determinant of the three-dimensional distribution of oxidation sites in the fiber.Description
Publisher Copyright: © The Author(s) 2024.
Keywords
AA9 LPMOs, Carbonyl detection, CBM, Cellulose, Enzymatic fiber engineering, Fluorescence, Functional variation, Oxidation, Size exclusion chromatography
Other note
Citation
Støpamo, F G, Sulaeva, I, Budischowsky, D, Rahikainen, J, Marjamaa, K, Kruus, K, Potthast, A, Eijsink, V G H & Várnai, A 2024, ' The impact of the carbohydrate-binding module on how a lytic polysaccharide monooxygenase modifies cellulose fibers ', Biotechnology for Biofuels and Bioproducts, vol. 17, no. 1, 118 . https://doi.org/10.1186/s13068-024-02564-8