Oae S, Mikami A, Matsuura T, Ogawa-Asada K, Watanabe Y, Fujimori K, Iyanagi T
Biochem Biophys Res Commun. 1985 Sep 16;131(2):567-73. doi: 10.1016/0006-291x(85)91274-4.
Mechanistic mode for the oxygenation of sulfides with the pig liver microsomal FAD-containing monooxygenase(EC 1.14.13.8) has been conveniently distinguished from that with the phenobarbital induced liver microsomal cytochrome P-450 by analyzing products of the oxygenation of phenacyl phenyl sulfide. Upon oxygenation of phenacyl phenyl sulfide, the FAD-containing monooxygenase gave solely phenacyl phenyl sulfoxide in contrast to the cytochrome P-450 promoted oxygenation which is known to give substantial amounts of C-S bond fission products. The observation suggests that the oxygenation of sulfide with FAD-containing monooxygenase involves the nucleophilic attack of the divalent sulfur on the reactive oxygen atom involved at the enzyme active site, namely electrophilic oxygenation of sulfide, though the oxygenation with the cytochrome P-450 is initiated by a single electron transfer from the sulfide to the enzyme active species.
通过分析苯甲酰苯基硫醚的氧化产物，猪肝微粒体含黄素单加氧酶（EC 1.14.13.8）催化硫化物氧化的机制模式已很方便地与苯巴比妥诱导的肝微粒体细胞色素P-450催化的机制模式区分开来。在苯甲酰苯基硫醚氧化时，含黄素单加氧酶只产生苯甲酰苯基亚砜，这与细胞色素P-450促进的氧化反应形成对比，已知后者会产生大量的C-S键断裂产物。该观察结果表明，含黄素单加氧酶催化硫化物氧化涉及二价硫对酶活性位点所涉及的活性氧原子的亲核攻击，即硫化物的亲电氧化，而细胞色素P-450的氧化反应是由硫化物向酶活性物种的单电子转移引发的。
