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Hall K, Joseph C, Ayuso-Fernández I, Tamhankar A, Rieder L, Skaali R, Golten O, Neese F, Røhr ÅK, Jannuzzi SAV, DeBeer S, Eijsink VGH, Sørlie M. A Conserved Second Sphere Residue Tunes Copper Site Reactivity in Lytic Polysaccharide Monooxygenases. J Am Chem Soc 2023; 145:18888-18903. [PMID: 37584157 PMCID: PMC10472438 DOI: 10.1021/jacs.3c05342] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Indexed: 08/17/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are powerful monocopper enzymes that can activate strong C-H bonds through a mechanism that remains largely unknown. Herein, we investigated the role of a conserved glutamine/glutamate in the second coordination sphere. Mutation of the Gln in NcAA9C to Glu, Asp, or Asn showed that the nature and distance of the headgroup to the copper fine-tune LPMO functionality and copper reactivity. The presence of Glu or Asp close to the copper lowered the reduction potential and decreased the ratio between the reduction and reoxidation rates by up to 500-fold. All mutants showed increased enzyme inactivation, likely due to changes in the confinement of radical intermediates, and displayed changes in a protective hole-hopping pathway. Electron paramagnetic resonance (EPR) and X-ray absorption spectroscopic (XAS) studies gave virtually identical results for all NcAA9C variants, showing that the mutations do not directly perturb the Cu(II) ligand field. DFT calculations indicated that the higher experimental reoxidation rate observed for the Glu mutant could be reconciled if this residue is protonated. Further, for the glutamic acid form, we identified a Cu(III)-hydroxide species formed in a single step on the H2O2 splitting path. This is in contrast to the Cu(II)-hydroxide and hydroxyl intermediates, which are predicted for the WT and the unprotonated glutamate variant. These results show that this second sphere residue is a crucial determinant of the catalytic functioning of the copper-binding histidine brace and provide insights that may help in understanding LPMOs and LPMO-inspired synthetic catalysts.
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Affiliation(s)
- Kelsi
R. Hall
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Chris Joseph
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Iván Ayuso-Fernández
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Ashish Tamhankar
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Lukas Rieder
- Institute
for Molecular Biotechnology, Graz University
of Technology, 8010, Graz, Austria
| | - Rannei Skaali
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Ole Golten
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Åsmund K. Røhr
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Sergio A. V. Jannuzzi
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Vincent G. H. Eijsink
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Morten Sørlie
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
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Ngo ST, Phan HN, Luu CX, Le CN, Ho GT, Ngo NTC, Le LQ, Mai BK, Phung HTT, Nguyen HD, Vu KB, Vu VV. Distal Hydrophobic Loop Modulates the Copper Active Site and Reaction of AA13 Polysaccharide Monooxygenases. J Phys Chem B 2022; 126:7567-7578. [PMID: 36137238 DOI: 10.1021/acs.jpcb.2c04215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polysaccharide monooxygenases (PMOs) use a type-2 copper center to activate O2 for the selective hydroxylation of one of the two C-H bonds of glycosidic linkages. Our electron paramagnetic resonance (EPR) analysis and molecular dynamics (MD) simulations suggest the unprecedented dynamic roles of the loop containing the residue G89 (G89 loop) on the active site structure and reaction cycle of starch-active PMOs (AA13 PMOs). In the Cu(II) state, the G89 loop could switch between an "open" and "closed" conformation, which is associated with the binding and dissociation of an aqueous ligand in the distal site, respectively. The conformation of the G89 loop influences the positioning of the copper center on the preferred substrate of AA13 PMOs. The dissociation of the distal ligand results in the bending of the T-shaped core of the Cu(II) active site, which could help facilitate its reduction to the active Cu(I) state. In the Cu(I) state, the G89 loop is in the "closed" conformation with a confined copper center, which could allow for efficient O2 binding. In addition, the G89 loop remains in the "closed" conformation in the Cu(II)-superoxo intermediate, which could prevent off-pathway superoxide release via exchange with the distal aqueous ligand. Finally, at the end of the reaction cycle, aqueous ligand binding to the distal site could switch the G89 loop to the "open" conformation and facilitate product release.
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Affiliation(s)
- Son Tung Ngo
- Laboratory of Theoretical and Computational Biophysics, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam.,Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam
| | - Han N Phan
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Cuong X Luu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Chinh N Le
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Giap T Ho
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Nhung T C Ngo
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Loan Q Le
- Institute of Tropical Biology, Vietnam Academy of Science and Technology, 9/621 Hanoi Highway, Thu Duc District, Ho Chi Minh City 700000, Vietnam
| | - Binh Khanh Mai
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
| | - Huong T T Phung
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
| | - Hoang-Dung Nguyen
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam.,Institute of Tropical Biology, Vietnam Academy of Science and Technology, 9/621 Hanoi Highway, Thu Duc District, Ho Chi Minh City 700000, Vietnam
| | - Khanh B Vu
- Department of Chemical Engineering, School of Biotechnology, International University, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 700000, Vietnam.,Vietnam National University, Quarter 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City 700000, Vietnam
| | - Van V Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City 700000, Vietnam
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Ngo ST. 501Y.V2 spike protein resists the neutralizing antibody in atomistic simulations. Comput Biol Chem 2022; 97:107636. [PMID: 35066438 PMCID: PMC8769535 DOI: 10.1016/j.compbiolchem.2022.107636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/16/2022] [Accepted: 01/17/2022] [Indexed: 11/26/2022]
Abstract
SARS-CoV-2 outbreaks worldwide caused COVID-19 pandemic, which is related to several million deaths. In particular, SARS-CoV-2 Spike (S) protein is a major biological target for COVID-19 vaccine design. Unfortunately, recent reports indicated that Spike (S) protein mutations can lead to antibody resistance. However, understanding the process is limited, especially at the atomic scale. The structural change of S protein and neutralizing antibody fragment (FAb) complexes was thus probed using molecular dynamics (MD) simulations. In particular, the backbone RMSD of the 501Y.V2 complex was significantly larger than that of the wild-type one implying a large structural change of the mutation system. Moreover, the mean of Rg, CCS, and SASA are almost the same when compared two complexes, but the distributions of these values are absolutely different. Furthermore, the free energy landscape of the complexes was significantly changed when the 501Y.V2 variant was induced. The binding pose between S protein and FAb was thus altered. The FAb-binding affinity to S protein was thus reduced due to revealing over steered-MD (SMD) simulations. The observation is in good agreement with the respective experiment that the 501Y.V2 SARS-CoV-2 variant can escape from neutralizing antibody (NAb).
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