5CT8: G158E/K44E/R57E/Y49E Bacillus subtilis lipase A with 0% [BMIM][Cl]

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.
PDB ID: 5CT8Download
MMDB ID: 133935
PDB Deposition Date: 2015/7/23
Updated in MMDB: 2015/11
Experimental Method:
x-ray diffraction
Resolution: 1.29  Å
Source Organism:
Similar Structures:
Biological Unit for 5CT8: monomeric; determined by author
Molecular Components in 5CT8
Label Count Molecule
Protein (1 molecule)
Quadruple Mutant Lipase a
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB