Schneider Claus, Pratt Derek A, Porter Ned A, Brash Alan R
Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
Chem Biol. 2007 May;14(5):473-88. doi: 10.1016/j.chembiol.2007.04.007.
Lipoxygenases (LOX) and cyclooxygenases (COX) react an achiral polyunsaturated fatty acid with oxygen to form a chiral peroxide product of high regio- and stereochemical purity. Both enzymes employ free radical chemistry reminiscent of hydrocarbon autoxidation but execute efficient control during catalysis to form a specific product over the multitude of isomers found in the nonenzymatic reaction. Exactly how both dioxygenases achieve this positional and stereo control is far from clear. We present four mechanistic models, not mutually exclusive, that could account for the specific reactions of molecular oxygen with a fatty acid in the LOX or COX active site.
脂氧合酶（LOX）和环氧化酶（COX）使一种非手性多不饱和脂肪酸与氧气发生反应，形成具有高区域和立体化学纯度的手性过氧化物产物。这两种酶都利用类似于烃类自动氧化的自由基化学，但在催化过程中进行有效控制，以形成特定产物，而非酶促反应中存在的众多异构体。这两种双加氧酶究竟如何实现这种位置和立体控制尚不清楚。我们提出了四种并非相互排斥的机制模型，这些模型可以解释分子氧与脂氧合酶或环氧化酶活性位点中的脂肪酸之间的特定反应。
