| Sumario: | 1. 1. Kinetic studies were carried out on the soluble and immobilized Rhodanese. 2. 2. The soluble enzyme showed a typical Michaelis-Menten behaviour, an inhibitory effect was observed at high thiosulphate and cyanide concentrations. 3. 3. The product sulphite was also an inhibitor, instead thiocyanate increased the enzyme velocity when it was added to the incubation mixture. 4. 4. A ping-pong mechanism was proposed for Rp. palustris Rhodanese with a stable (free enzyme: E) and an unstable (sulfur substituted enzyme: ES) kinetic enzyme form. 5. 5. The insolubilized Rhodanese presented an unusual kinetic behaviour, with sigmoid shape substrate profiles and non-linear double reciprocal plots. 6. 6. From the empirical Hill equation, positive cooperativity (n>1) was found for both substrates. © 1987.
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