Thiosulphate sulphurtransferase

Schievelbein, H., Batuneister, R., and Vogel, R., 1969, Comparative investigations on the activity of thiosulphate sulphurtransferase, Naturvissenschaf-ten,56 4l6. 

According to present knowledge transfer of bivalent or sulphane sulphiir from thiosulphate, thiocystine, 3-mercaptopyruvate and some other donors is catalyzed by at least three different enzymes rhodanese /EC 2.8, 1.1/, thiosulphate reductase /no EC number/ and mercapto-pyruvate sulphurtransferase /feC 2.8.1,2/ /for references see Westley, 1973 Koj et al.,1975/ Th mechanism of their action is not uniform rhodanese operates by a double-displacement mechanism /cf. Westley, 1973/ mercaptopyruvate sulphurtransferase by a sequential reaction /Jarabak and Westley,1978/, while the mode of action of thiosulphate reductase is not elucidated. 

Lang demonstrated that an enzyme which he called rhodanese (thiosulphate cyanide sulphurtransferase, E.C.-2.8.1.1.) accelerates the formation of thiocyanate from cyanide and thiosulphate, liver and kidney homogenates being p2irticularly active [41]. 

Later studies showed that thiosulphate is derived enzymically from mercaptopyruvate (3-mercaptopyruvate cyanide sulphurtransferase E.C.2.8.I.2.), the same enzyme also catalysing the formation of thiocyanate directly from cyanide 2md mercaptopyruvate [42]. Mercaptopyruvate is produced by the deamination of cysteine (Figure 1.1). 

---