Cannella C, Berni R
FEBS Lett. 1983 Oct 3;162(1):180-4. doi: 10.1016/0014-5793(83)81074-6.
Cyanide-promoted inactivation of the enzyme rhodanese [thiosulfate sulfurtransferase (EC 2.8.1.1)] in the presence of ketoaldehydes is caused by reduced forms of molecular oxygen generated during autoxidation of the reaction products. The requirement of both catalase and superoxide dismutase to prevent rhodanese inactivation indicates that hydroxyl radical could be the most efficient inactivating agent. Rhodanese, also in the less stable sulfur-free form, shows a different sensitivity towards oxygen activated species. While the enzyme is unaffected by superoxide radical, it is rapidly inactivated by hydrogen peroxide. The extent of inactivation depends on the molar ratio between sulfur-free enzyme and oxidizing agent. Fully inactive enzyme is reactivated by reduction with its substrate thiosulfate.
在酮醛存在的情况下，氰化物促进硫氰酸酶[硫代硫酸硫转移酶（EC 2.8.1.1）]失活是由反应产物自氧化过程中产生的分子氧还原形式所致。过氧化氢酶和超氧化物歧化酶都需要用来防止硫氰酸酶失活，这表明羟基自由基可能是最有效的失活剂。硫氰酸酶，即使处于较不稳定的无硫形式，对氧活化物种也表现出不同的敏感性。虽然该酶不受超氧阴离子自由基的影响，但它会被过氧化氢迅速失活。失活程度取决于无硫酶与氧化剂之间的摩尔比。完全失活的酶通过用其底物硫代硫酸盐还原而重新激活。
