Some Kinetic Properties of Rhodanese in the Liver of Gallus domesticus

Abstract

The kinetics of rhodanese In the liver of domestic fowl was assayed spectrophotometrically by following the appearance of thiocyanate at 460nm. The activity of the enzyme was 5.12 umol SCNmin-1g-1 fresh tissues. The activity of the enzyme was highest at pH 7.0 and 40°C. The activation energy of the enzyme was calculated to be 2S.53KJ/mol. Double reciprocal plots of the enzyme using varied concentrations of each of the two substrates suggest that the enzyme may function through ping-pong mechanism, in which thiosulphate binds first to the enzyme surface leaving it as a modified sulphurated enzyme, without the formation of a ternary complex, before the binding of cyanide. These results may reflect the physiological behaviour of the enzyme.