Premium
Crystallographic Investigation of Imidazolium Ionic Liquid Effects on Enzyme Structure
Author(s) -
Nordwald Erik M.,
Plaks Joseph G.,
Snell Jared R.,
Sousa Marcelo C.,
Kaar Joel L.
Publication year - 2015
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.201500398
Subject(s) - ionic liquid , chemistry , enzyme , ionic bonding , crystallography , materials science , biochemistry , catalysis , organic chemistry , ion
We present the first crystallographic insight into the interactions of an ionic liquid (IL) with an enzyme, which has widespread implications for stabilizing enzymes in IL media for biocatalysis. Structures of Bacillus subtilis lipase A (lipA) and an IL‐stable variant (QM‐lipA) were obtained in the presence of increasing concentrations of 1‐butyl‐3‐methylimidazolium chloride ([BMIM][Cl]). These studies revealed that the [BMIM] cation interacts with surface residues through hydrophobic and cation–π interactions. Of specific interest was the disruption of internal stacking interactions of aromatic side chains by [BMIM], which provides structural evidence for the mechanism of enzyme denaturation by ILs. The interaction of [BMIM] and Cl ions with lipA was reduced by the stabilizing mutations Y49E and G158E in QM‐lipA. Ultimately, these findings present the molecular basis for stabilizing enzymes from IL‐induced inactivation, as well as the selection of ILs that are less denaturing.