Optimization of the enzymatic synthesis of d-p-hydroxyphenylglycine from dl-5-substituted hydantoin using d-hydantoinase and N-carbamoylase
1995; Elsevier BV; Volume: 17; Issue: 1 Linguagem: Inglês
10.1016/0141-0229(94)00040-x
ISSN1879-0909
Autores Tópico(s)Enzyme Structure and Function
Resumod-Hydantoinase and N-carbamoylase possessed in bacterium Agrobacterium sp I-671 were partially purified to about 90% purity on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and biochemical properties were characterized. The N-carbamoylase was found to be severely inhibited by ammonium ions coproduced with d-p-hydroxyphenylglycine (d-HPG). For the enhancement of conversion yield, adsorptive removal of ammonium ions from the reaction mixture was attempted, and the conversion yield of d-HPG significantly increased by the addition of specific adsorbents for ammonium ions. To determine the optimal ratio of d-hydantoinase to N-carbamoylase which minimizes the accumulation of intermediate (N-carbamoyl-d-p-hydroxyphenylglycine) in the direct enzymatic production of d-HPG, a sequential reaction was numerically simulated. Simulation results coincided well with experimental data, and the optimal ratio between d-hydantoinase and N-carbamoylase was found to be about 1:3 on a weight basis.
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