Tree Display

AceDB Schema

XML Display


LongText Report for: Li_2018_ACS.Catal_8_8314

Name Class
An epoxide hydrolase from Vigna radiata (VrEH2) affords partial enantioconvergence (84% ee) in the enzymatic hydrolysis of racemic p-nitrostyrene oxide (pNSO), mainly due to insufficient regioselectivity for the (S)-enantiomer (rS = alphaS/betaS = 7.3). To improve the (S)-pNSO regioselectivity, a small but smart library of VrEH2 mutants was constructed by substituting each of four key residues lining the substrate binding site with a simplified amino acid alphabet of Val, Asn, Phe, and Trp. Among the mutants, M263N attacked almost exclusively at Calpha in the (S)-epoxide ring with satisfactory regioselectivity (rS = 99.0), without compromising the original high regioselectivity for the (R)-epoxide (rR = 99.0), resulting in near-perfect enantioconvergence (>99% analytical yield, 98% ee). Structural and conformational analysis showed that the introduced Asn263 formed additional hydrogen bonds with the nitro group in substrate, causing a shift in the substrate binding pose. This shift increased the difference in attacking distances between Calpha and Cbeta, leading to an improved regiopreference toward (S)-pNSO and affording near-perfect enantioconvergence.

Send your questions or comments to :
Mail to: Nicolas Lenfant, Thierry Hotelier, Yves Bourne, Pascale Marchot and Arnaud Chatonnet.
Please cite: Lenfant 2013 Nucleic.Acids.Res. or Marchot Chatonnet 2012 Prot.Pept Lett.
For technical information about these pages see:
ESTHER Home Page and ACEDB Home Page
AcePerl Lincoln Stein Home Page

Acknowledgements and disclaimer