Is thiosulfate sulfurtransferase the colonic sulfide oxidase

Neither sodium sulfide nor sodium thiosulfate is soluble in ethanol but NaHS.H20 is. We then removed insoluble material from our preparations by centrifugation and discarded it. The ethanol-soluble material was used in the experiments. In this later study we were able to show that removal of thiosulfate sulfurtransferase (TST), using a specific antiserum, from preparations of purified rhodanese removed its ability to metabolise sulfide whereas removal of mercaptopyruvate sulfurtransferase (MST) from this preparation did not. (TST and MST are sulfurtransferases which copurify as rhodanese due to close structural and size similarities [3]). We concluded that TST was the component of rhodanese responsible for actions against sulfide. If Wilson et al. had contacted us they would have found us receptive to the concept of sulfide oxidase. We ourselves have reservations about the role of TST as completely explaining sulfide metabolism in vivo. We would have enjoyed collaboration to take this research forward and are disappointed that they chose not to do this.