Abstract
Recombinant D-hydantoinase (AH) from Agrobaterium radiobacter DH102 was used to produce N-carbamoyl-D-p-hydroxyphenylglycin (NC-HPG) from D,L-hydroxyphenylhydantoin (D,L-HPH).Determination of the relative molecular mass of the protein by gel-filtration chromatography gave anapparent value of 101.57 kD. The subunit Mr was 56 kD, as estimated by analytical SDS/PAGE. Theenzyme was purified by a procedure including streptomycin sulfate treatment, ammonium sulfatefractionation, six chromatographies, and was partially purified to about 90% purity on SDS-PAGE. Some biochemical properties were characterized. The optimal growth temperature of the bacteriumwas about 28℃. The optimal pH and temperature of recombinant D-hydantoinase were determined tobe about 8.0 and 55℃, respectively. And the half-life of the enzyme was about 5hr at 37℃. The purifiedrecombinant D-hydantoinase was not stable even at 4℃, however. Our results of the experiments showedthe low activity and stability of the enzyme, suggesting further useful strategy should be attempted.