High Rates and Substrate Selectivities in Water by Polyvinylimidazoles as Transaminase Enzyme Mimics with Hydrophobically Bound Pyridoxamine Derivatives as Coenzyme Mimics
作者:Rachid Skouta、Sujun Wei、Ronald Breslow
DOI:10.1021/ja9072589
日期:2009.11.4
4-vinylimidazole and copolymers with 1-dodecyl-4-vinylimidazole were used as enzymemimics to transaminate pyruvic acid to alanine, phenylpyruvic acid to phenylalanine, and indole-3-pyruvic acid to tryptophan in water at pH 7.5 and 20 degrees C using pyridoxamines carrying hydrophobic side chains as coenzyme mimics. The best enzymemimic accelerated the transamination of indole-3-pyruvic acid by a factor of
Pyridoxamines carrying hydrophobic side chains reversibly bind into the hydrophobic core of polyethylenimines and transaminate ketoacids to amino acids with as much as a 725000-fold rate acceleration. Turnover catalysis was achieved by sacrificial oxidative decarboxylation of C-substituted amino acids, which reconverted the pyridoxals to pyridoxamines.