Physicochemical features of rhodanese: A review

Abstract

Rhodanese is a multifunctional, mitochondrial, sulphur transferase that catalyses the detoxification of 
cyanide by sulphuration in a double displacement (ping pong) mechanistic reaction. It is widely 
distributed occurring in varieties of plants and animals, where it activity is modulated by a number of 
factors including differences in species, organs, sex, age and diet. The enzyme is a single polypeptide 
chain of 289 amino acids with molecular weight of up to 37,000. The active site of rhodanese contains a 
tryptophanyl residue in close proximity with an essential sulphahydryl group. Many methods for 
assaying rhodanese have been reported, the most prominent being the one based on the colorimetric 
estimation of thiocyanate formed from the reaction of cyanide and thiosulphate, catalysed by 
rhodanese.