Vedvick T S, Itano H A
Biochim Biophys Acta. 1981 Jan 21;672(2):214-8. doi: 10.1016/0304-4165(81)90395-0.
We have compared the rates of reaction of ortho and para substituted halophenylhydrazines with oxygen, and we have found that the reaction rates of these phenylhydrazines are accelerated by metal ions and oxyhemoglobin. Stimulation of the reaction rate by oxyhemoglobin was 20-times that by Fe3+ at the same concentration. In the presence of oxyhemoglobin, the initial decrease in the concentration of oxygen was followed by an increase. We propose that phenyldiazene produced from the oxidation of phenylhydrazine by oxyhemoglobin reduced oxygen to superoxide and caused the initial rapid decrease in oxygen concentration. The partial restoration of oxygen in the reaction mixture could be accounted for by the dismutation of superoxide to oxygen and hydrogen peroxide, and of hydrogen peroxide to oxygen and water.
我们比较了邻位和对位取代卤代苯肼与氧气的反应速率，发现这些苯肼的反应速率会被金属离子和氧合血红蛋白加速。在相同浓度下，氧合血红蛋白对反应速率的促进作用是Fe3+的20倍。在有氧合血红蛋白存在的情况下，氧气浓度最初下降，随后上升。我们认为，氧合血红蛋白氧化苯肼产生的苯二氮烯将氧气还原为超氧化物，导致氧气浓度最初迅速下降。反应混合物中氧气的部分恢复可以通过超氧化物歧化为氧气和过氧化氢，以及过氧化氢歧化为氧气和水来解释。
