Mechanistic Elucidation and Stereochemical Consequences of Alternative Binding of Alkenyl Substrates by Engineered Arylmalonate Decarboxylase.

ABSTRACT: The cofactor-free arylmalonate decarboxylase (AMDase) is a valuable biocatalyst for synthesizing α-aryl and α-alkenyl alkanoic acids with excellent stereoselectivity. We engineered a new hydrophobic pocket in (S)-selective AMDase mutants, creating AMDase ICPLLG with enhanced activity. For the investigation of the mechanism, we synthesized isotope-labeled, pseudochiral 2-methyl-2-vinyl malonate via an auxiliary-based asymmetric route using a chiral imidazolidinone to enable stereoselective bis-alkylation of malonates. Our results reveal striking substrate-dependent stereochemical behavior: AMDase ICPLLG decarboxylates prochiral aromatic malonates with retention of configuration at the α-carbon. The critical Cys residue adds a proton from the same face of the substrate as the leaving

SUBMITTER: van der Pol E 

PROVIDER: S-EPMC12576825 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature