Abstract

Lytic polysaccharide monooxygenases (LPMOs) are widely distributed in Nature, where they catalyze the hydroxylation of glycosidic bonds in polysaccharides. Despite the importance of LPMOs in the global carbon cycle and in industrial biomass conversion, the catalytic properties of these monocopper enzymes remain enigmatic. Strikingly, there is a remarkable lack of kinetic data, likely due to a multitude of experimental challenges related to the insoluble nature of LPMO substrates, like cellulose and chitin, and to the occurrence of multiple side reactions. Here, we employed competition between well characterized reference enzymes and LPMOs for the H2O2 co-substrate to kinetically characterize LPMO-catalyzed cellulose oxidation. LPMOs of both bacterial and fungal origin showed high peroxygenase efficiencies, with kcat/KmH2O2 values in the order of 105–106 M−1 s−1. Besides providing crucial insight into the cellulolytic peroxygenase reaction, these results show that LPMOs belonging to multiple families and active on multiple substrates are true peroxygenases.

Lytic polysaccharide monooxygenases (LPMOs) catalyze the hydroxylation of glycosidic bonds in polysaccharides, but the catalytic properties of these monocopper enzymes remain poorly characterized. Here authors employ competition between reference enzymes and LPMOs for the H2O2 co-substrate to kinetically characterize LPMO-catalyzed cellulose oxidation.

Details

Title
Kinetic insights into the peroxygenase activity of cellulose-active lytic polysaccharide monooxygenases (LPMOs)
Author
Kont Riin 1 ; Bastien, Bissaro 2   VIAFID ORCID Logo  ; Eijsink Vincent G H 3   VIAFID ORCID Logo  ; Väljamäe Priit 1   VIAFID ORCID Logo 

 University of Tartu, Institute of Molecular and Cell Biology, Tartu, Estonia (GRID:grid.10939.32) (ISNI:0000 0001 0943 7661) 
 NMBU—Norwegian University of Life Sciences, Faculty of Chemistry, Biotechnology and Food Science, Ås, Norway (GRID:grid.19477.3c) (ISNI:0000 0004 0607 975X); INRAE, Aix Marseille University, UMR1163 Biodiversité et Biotechnologie Fongiques, Marseille, France (GRID:grid.5399.6) (ISNI:0000 0001 2176 4817) 
 NMBU—Norwegian University of Life Sciences, Faculty of Chemistry, Biotechnology and Food Science, Ås, Norway (GRID:grid.19477.3c) (ISNI:0000 0004 0607 975X) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2471564575
Copyright
© The Author(s) 2020. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.