Thiosulfate sulfurtransferase (TST), also known as Rhodanese, is a mitochondrial enzyme that involved in cyanide detoxification and the modification of sulfur-containing enzymes. This protein contains two highly conservative domains, known as rhodanese homology domains. In mammals, most cyanide is converted to thiocyanate by this enzyme. TST also has weak mercaptopyruvate sulfurtransferase activity. Recombinant TST protein was expressed in E.coli and purified by using conventional chromatography techniques.