Structural Dynamics of Lytic Polysaccharide Monooxygenase during Catalysis

0533359 - MBÚ 2021 RIV CH eng J - Journal Article
Filandr, František - Kavan, Daniel - Kracher, D. - Laurent, Ch. V. F. P. - Ludwig, R. - Man, Petr - Halada, Petr
Structural Dynamics of Lytic Polysaccharide Monooxygenase during Catalysis.
Biomolecules. Roč. 10, č. 2 (2020), č. článku 242. E-ISSN 2218-273X
R&D Projects: GA ČR(CZ) GF16-34818L; GA MŠMT(CZ) ED1.1.00/02.0109; GA MŠMT(CZ) LQ1604
Research Infrastructure: CIISB - 90043
Institutional support: RVO:61388971
Keywords : aspartic protease nepenthesin-1 * oxidative cleavage * cellulose * peptides * lytic polysaccharide monooxygenase * lignocellulose degradation * deuterium exchange mass spectrometry * oxidative amino acid modification * peptide bond cleavage * reactive oxygen species
OECD category: Microbiology
Impact factor: 4.879, year: 2020
Method of publishing: Open access
https://www.mdpi.com/2218-273X/10/2/242

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.
Permanent Link: http://hdl.handle.net/11104/0311765