Abstract
A fungal rhodanese from the spray-dried powder of a culture filtrate of Trametes sanguinea was purified to 142-fold by ammonium sulfate precipitation and DEAE-cellulose and Sephadex G-100 column chromatography. The purified rhodanese (pl 5.10) showed a single band on disc electrophoresis, and its molecular weight was estimated to be 51, 700 by gel filtration technique. The enzyme had a broad pH optimum between 7.5 and 8.5 and was stable at pH values from 4 to 8 at 30°C for 44 hr. Its activity was inhibited by p-chloromercuribenzoate at pH 9.5, but not at pH 8.0, and was inhibited by cysteine, β-mercaptoethanol and sodium borohydride at pH 8.0. Both thiosulfate and cyanide showed substrate inhibition at high concentrations. Dihydrolipoate and benzenethiosulfonate were also good substrates.
