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Publication Abstract from PubMed

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-pi 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.

Crystallographic Investigation of Imidazolium Ionic Liquid Effects on Enzyme Structure.,Nordwald EM, Plaks JG, Snell JR, Sousa MC, Kaar JL Chembiochem. 2015 Nov;16(17):2456-9. doi: 10.1002/cbic.201500398. Epub 2015 Oct, 14. PMID:26388426^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.