Kinetic characteristics of Synodontis membranaceus gills and liver rhodanese

The biochemical reaction catalyzed by cyanide:thiosulphate sulfurtransferase commonly referred to as rhodanese is the most significant mechanism for cyanide detoxification. This investigation’s aim is to establish the presence of the enzyme rhodanese in synodontis membranaceus and to elucidate its kinetic parameters in the liver and gills of the synodontis specie.  Rhodanese activity was assayed by measuring the amount of thiocyante formed in micromoles at 37°C and pH 8.2. The results revealed that the km and Vmax values recorded for Synodontis membranaceus liver rhodanese were 11.12+2.58 and 0.15umol/min+0.01 for cyanide and 27.78mM+5.15 and 0.22umil/min+0.00 for thiosulphate. Also the, km and Vmax values for gills rhodanese were 15.38mM+1.38 and 0.13umol/min+0.00 for cyanide and 25mM+3.65 and 0.19umol/mind were for thiosulphate. Substrate specificity studies revealed thiosulphate as the best sulphur donor. Both liver and gills rhodanese showed maximum activity at pH 8.0. The liver enzyme showed maximum activity at 30°C, while the gills enzyme showed maximum activity through 30-35°C. Rhodanese activity is present in the synodontis specie investigated with properties comparable to rhodanese present in other aquatic organisms.