Effect of treatment with compressed CO2 and propane on d-hydantoinase activity

The objective of this work was to assess the influence of compressed CO2 and propane treatment on the specific activity of partially purified d-hydantoinase from adzuki bean (Vigna angularis). The lyophilized protein was obtained through the precipitation of proteins with (NH4)2SO4 followed by lyophilization of the precipitate. The d-hydantoinase activity was determined using hydantoin as substrate at 40 °C and pH 9.0. The effect of temperature, pressure, and exposure time on the solubilized and lyophilized partially purified d-hydantoinase extract in compressed CO2 and propane were evaluated. Treatment of this extract from adzuki bean (V. angularis) in compressed CO2 and propane showed good stability of this enzyme in the two solvents. The resolubilized enzyme extract presented important activity losses with compressed CO2 treatment and better stability when treated with compressed propane.