Kinetic model for enzymatic synthesis of S-Bzl-γ-L-glutamyl-L-cysteine

S-bzl-γ-L-glutamyl-L-Cysteine (S-Bzl-GGC) was synthesized with L-glutamine and S-bzl-cysteine catalyzed by γ-glutamyltranspeptidase from Bacillus subtilis NX-2. On the basis of mechanism analysis, a novel model for describing this process was developed. The validation experiment revealed that a good agreement between experimental data and calculations obtained, and the average relative error in model application test was 5.57%. According to the kinetic model, the increase of donor concentration was conducive to the transpeptidation, but there were more autotranspeptidation. The increase of receptor concentration was some simulative to the production of S-Bzl-GGC, but with no significant influence on autotranspeptidation. The enzymatic process could be accelerated by increasing the enzyme concentration, whereas the maximal concentration of product would not be changed.