REQUIREMENTS FOR HYDROPEROXIDE BY THE CYCLOOXYGENASE AND PEROXIDASE-ACTIVITIES OF PROSTAGLANDIN-H SYNTHASE
REQUIREMENTS FOR HYDROPEROXIDE BY THE CYCLOOXYGENASE AND PEROXIDASE-ACTIVITIES OF PROSTAGLANDIN-H SYNTHASE
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DOI：
10.1016/0090-6980(83)90025-4
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发表时间：
1983-01-01
影响因子：
2.9
通讯作者：
LANDS, WEM
中科院分区：
文献类型：
--
作者：
KULMACZ, RJ;LANDS, WEM
纯化的前列腺素H合酶含有环加氧酶活性，形成氢过氧化物，前列腺素G和过氧化物酶活性，去除氢过氧化物。由于氢过氧化物是环加氧酶活性的必要激活剂，因此两种明显相反的活性的矛盾存在需要仔细解释。动力学研究表明，使环加氧酶充分发挥活性所需的过氧化氢浓度远低于使过氧化物酶发挥50%效力的浓度。因此，合酶的过氧化物酶活性在将氢过氧化物浓度降低到仍然允许快速环加氧酶作用的水平以下时是非常无效的。
Purified prostaglandin H synthase contains cyclooxygenase activity that forms the hydroperoxide, prostaglandin G and peroxidase activity which removes hydroperoxides. Since hydroperoxides are necessary activators of cyclooxygenase activity, the paradoxical presence of 2 apparently opposing activities requires careful interpretation. Kinetic studies indicate that the concentration of hydroperoxide needed for full cyclooxygenase activity is much less than that which gives 50% effectiveness with the peroxidase. Thus, the peroxidase activity of the synthase is very ineffective in decreasing the hydroperoxide concentration below levels that still permit rapid cyclooxygenase action.