Download MendeleyRational mutagenesis of an epoxide hydrolase and its structural mechanism for the enantioselectivity improvement toward chiral ortho-fluorostyrene oxide.
Lu, Z.Y., Liao, X., Jing, W.W., Liu, K.K., Ren, Q.G., He, Y.C., Hu, D.(2024) Int J Biol Macromol 282: 136864-136864
- PubMed: 39476898
- DOI: https://doi.org/10.1016/j.ijbiomac.2024.136864
- Primary Citation of Related Structures:
8XIZ - PubMed Abstract:
Chiral (S)-o-fluorostyrene oxide (oFSO) and vicinal diol (R)-o-fluorophenylethane-1,2-diol (oFPED) are important intermediates for synthesizing treatments for neuropathic diseases. This study aimed to engineer Aspergillus usamii epoxide hydrolase (AuEH2) through a rational mutagenesis strategy to customize high enantioselectivity mutant for rac-oFSO. Out of 181 single-site mutants screened, six showed elevated enantiomeric ratio (E value) ranging from 32 to 108 according to E value and activity mutability landscapes. By combinatorial mutagenesis of A250I with other five single-site mutants, we constructed five double-site mutants, with the best-performing mutant, D5 (A250I/L344V), achieving an E value of 180. This mutant enabled the efficient kinetic resolution of 400 mM rac-oFSO in pure water system using E. coli/Aueh2 A250I/L344V , yielding (S)-oFSO (>99 % ee s , 50 % yield s ) and (R)-oFPED (>99 % ee p , 50 % yield p ) with space-time yields (STYs) of 331.5 and 376.1 g/L/d, respectively. Combining crystal structure resolution with theoretical computations clarified the enantioselectivity mechanism of D5, demonstrating that A250I reduced the funnel-shaped substrate binding pocket (SBP) while L344V extended its bottom, enhancing specific recognition of (R)-oFSO and inhibiting (S)-oFSO hydrolysis. These findings provide valuable insights for designing highly enantioselective enzyme mutants, advancing the field of asymmetric synthesis of chiral compounds using green biocatalytic processes.
- School of Pharmacy & School of Biological and Food Engineering, Changzhou University, Changzhou 213164, PR China.
Organizational Affiliation:
