Tong, Xiaoxue, Busk, Peter Kamp, Lange, Lene and Pang, Jiayun ORCID: https://orcid.org/0000-0003-0689-8440 (2016) New insights into the molecular mechanism of methanol-induced inactivation of Thermomyces lanuginosus lipase: A molecular dynamics simulation study. Molecular Simulation, 42 (5). pp. 434-445. ISSN 0892-7022 (Print), 1029-0435 (Online) (doi:10.1080/08927022.2015.1059938)

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Abstract

Methanol intolerance of lipase is a major limitation in lipase-catalyzed methanolysis reactions. In this study, to understand the molecular mechanism of methanol-induced inactivation of lipases, we performed molecular dynamics (MD) simulations of Thermomyces lanuginosus lipase (TLL) in water and methanol and compared the observed structural and dynamic properties. The solvent accessibility analysis showed that in methanol, polar residues tended to be buried away from the solvent while non-polar residues tended to be more solvent-exposed in comparison to those in water. Moreover, we observed that in methanol, the van der Waals packing of the core residues in two hydrophobic regions of TLL became weak. Additionally, the catalytically relevant hydrogen bond between Asp201 OD2 and His258 ND1 in the active site was broken when the enzyme was solvated in methanol. This may affect the stability of the tetrahedral intermediates in the catalytic cycle of TLL. Furthermore, compared to those in water, some enzyme surface residues displayed enhanced movement in methanol with higher Cα root-mean-square atomic positional fluctuation values. One of such methanol-affecting surface residues (Ile241) was chosen for mutation, and MD simulation of the I241E mutant in methanol was conducted. The structural analysis of the mutant showed that replacing a non-polar surface residue with an acidic one at position 241 contributed to the stabilization of enzyme structure in methanol. Ultimately, these results, while providing molecular-level insights into the destabilizing effect of methanol on TLL, highlight the importance of surface residue redesign to improve the stability of lipases in methanol environments.

Item Type:	Article
Uncontrolled Keywords:	Thermomyces lanuginosus lipase; Methanol intolerance; Molecular dynamics simulation; Rational design; Protein stability
Subjects:	Q Science > QA Mathematics Q Science > QD Chemistry
Faculty / School / Research Centre / Research Group:	Faculty of Engineering & Science Faculty of Engineering & Science > School of Science (SCI)
Last Modified:	21 Oct 2020 22:09
URI:	http://gala.gre.ac.uk/id/eprint/13881

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