Next Article in Journal
Optimization of Catechin and Proanthocyanidin Recovery from Grape Seeds Using Microwave-Assisted Extraction
Previous Article in Journal
The Kinetics of Amyloid Fibril Formation by de Novo Protein Albebetin and Its Mutant Variants
Open AccessArticle

Structural Dynamics of Lytic Polysaccharide Monooxygenase during Catalysis

1
Institute of Microbiology of the CAS, Division BioCeV, Prumyslova 595, 252 50 Vestec, Czech Republic
2
Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43 Prague 2, Czech Republic
3
Biocatalysis and Biosensing Research Group, Department of Food Science and Technology, BOKU—University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
*
Authors to whom correspondence should be addressed.
Biomolecules 2020, 10(2), 242; https://doi.org/10.3390/biom10020242
Received: 15 January 2020 / Revised: 30 January 2020 / Accepted: 31 January 2020 / Published: 5 February 2020
(This article belongs to the Section Molecular Structure and Dynamics)
Lytic polysaccharide monooxygenases (LPMOs) are industrially important oxidoreductases employed in lignocellulose saccharification. Using advanced time-resolved mass spectrometric techniques, we elucidated the structural determinants for substrate-mediated stabilization of the fungal LPMO9C from Neurospora crassa during catalysis. LPMOs require a reduction in the active-site copper for catalytic activity. We show that copper reduction in NcLPMO9C leads to structural rearrangements and compaction around the active site. However, longer exposure to the reducing agent ascorbic acid also initiated an uncoupling reaction of the bound oxygen species, leading to oxidative damage, partial unfolding, and even fragmentation of NcLPMO9C. Interestingly, no changes in the hydrogen/deuterium exchange rate were detected upon incubation of oxidized or reduced LPMO with crystalline cellulose, indicating that the LPMO-substrate interactions are mainly side-chain mediated and neither affect intraprotein hydrogen bonding nor induce significant shielding of the protein surface. On the other hand, we observed a protective effect of the substrate, which slowed down the autooxidative damage induced by the uncoupling reaction. These observations further complement the picture of structural changes during LPMO catalysis.
Keywords: lytic polysaccharide monooxygenase; lignocellulose degradation; hydrogen/deuterium exchange mass spectrometry; oxidative amino acid modification; peptide bond cleavage; reactive oxygen species lytic polysaccharide monooxygenase; lignocellulose degradation; hydrogen/deuterium exchange mass spectrometry; oxidative amino acid modification; peptide bond cleavage; reactive oxygen species
MDPI and ACS Style

Filandr, F.; Kavan, D.; Kracher, D.; Laurent, C.V.; Ludwig, R.; Man, P.; Halada, P. Structural Dynamics of Lytic Polysaccharide Monooxygenase during Catalysis. Biomolecules 2020, 10, 242.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop