Multiscale Modelling of Lytic Polysaccharide Monooxygenases
(2017) In ACS Omega 2. p.536-545- Abstract
- Lytic polysaccharide monooxygenase (LPMO) enzymes have attracted considerable attention owing to their ability to enhance polysaccharide depolymerization, making them interesting with respect to production of biofuel from cellulose. LPMOs are metalloenzymes that contain a mononuclear copper active site, capable of activating dioxygen. However, many details of this activation are unclear. Some aspects of the mechanism have previously been investigated from a computational angle. Yet, either these studies have employed only molecular mechanics (MM), which are inaccurate for metal active sites, or they have described only the active site with quantum mechanics (QM) and neglected the effect of the protein. Here, we employ hybrid QM and MM... (More)
- Lytic polysaccharide monooxygenase (LPMO) enzymes have attracted considerable attention owing to their ability to enhance polysaccharide depolymerization, making them interesting with respect to production of biofuel from cellulose. LPMOs are metalloenzymes that contain a mononuclear copper active site, capable of activating dioxygen. However, many details of this activation are unclear. Some aspects of the mechanism have previously been investigated from a computational angle. Yet, either these studies have employed only molecular mechanics (MM), which are inaccurate for metal active sites, or they have described only the active site with quantum mechanics (QM) and neglected the effect of the protein. Here, we employ hybrid QM and MM (QM/MM) methods to investigate the first steps of the LPMO mechanism, which is reduction of CuII to CuI and the formation of a CuII–superoxide complex. In the latter complex, the superoxide can bind either in an equatorial or an axial position. For both steps, we obtain structures that are markedly different from previous suggestions, based on small QM-cluster calculations. Our calculations show that the equatorial isomer of the superoxide complex is over 60 kJ/mol more stable than the axial isomer because it is stabilized by interactions with a second-coordination-sphere glutamine residue, suggesting a possible role for this residue. The coordination of superoxide in this manner agrees with recent experimental suggestions. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/5bce233c-7381-4f23-a6b0-5c790fc0075e
- author
- Hedegård, Erik
LU
and Ryde, Ulf
LU
- organization
- publishing date
- 2017
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Coordination chemistry, Molecular dynamics simulation, Molecular mechanics, Molecular structure, Proteins, Reaction mechanism, Theory
- in
- ACS Omega
- volume
- 2
- pages
- 536 - 545
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85028937910
- wos:000395863300020
- ISSN
- 2470-1343
- DOI
- 10.1021/acsomega.6b00521
- language
- English
- LU publication?
- yes
- id
- 5bce233c-7381-4f23-a6b0-5c790fc0075e
- date added to LUP
- 2017-07-27 14:50:56
- date last changed
- 2023-04-07 20:14:34
@article{5bce233c-7381-4f23-a6b0-5c790fc0075e, abstract = {{Lytic polysaccharide monooxygenase (LPMO) enzymes have attracted considerable attention owing to their ability to enhance polysaccharide depolymerization, making them interesting with respect to production of biofuel from cellulose. LPMOs are metalloenzymes that contain a mononuclear copper active site, capable of activating dioxygen. However, many details of this activation are unclear. Some aspects of the mechanism have previously been investigated from a computational angle. Yet, either these studies have employed only molecular mechanics (MM), which are inaccurate for metal active sites, or they have described only the active site with quantum mechanics (QM) and neglected the effect of the protein. Here, we employ hybrid QM and MM (QM/MM) methods to investigate the first steps of the LPMO mechanism, which is reduction of CuII to CuI and the formation of a CuII–superoxide complex. In the latter complex, the superoxide can bind either in an equatorial or an axial position. For both steps, we obtain structures that are markedly different from previous suggestions, based on small QM-cluster calculations. Our calculations show that the equatorial isomer of the superoxide complex is over 60 kJ/mol more stable than the axial isomer because it is stabilized by interactions with a second-coordination-sphere glutamine residue, suggesting a possible role for this residue. The coordination of superoxide in this manner agrees with recent experimental suggestions.}}, author = {{Hedegård, Erik and Ryde, Ulf}}, issn = {{2470-1343}}, keywords = {{Coordination chemistry; Molecular dynamics simulation; Molecular mechanics; Molecular structure; Proteins; Reaction mechanism; Theory}}, language = {{eng}}, pages = {{536--545}}, publisher = {{The American Chemical Society (ACS)}}, series = {{ACS Omega}}, title = {{Multiscale Modelling of Lytic Polysaccharide Monooxygenases}}, url = {{http://dx.doi.org/10.1021/acsomega.6b00521}}, doi = {{10.1021/acsomega.6b00521}}, volume = {{2}}, year = {{2017}}, }