Karuzina I I, Bachmanova G I, Archakov A I
Vestn Ross Akad Med Nauk. 1995(2):17-29.
The paper deals with possible mechanisms of cytochrome p-450 self-activation during catalytic turnover. Two routes of hemoprotein inactivation are so far known. The first route studied extensively by many authors, consists in formation of active intermediates capable of modifying heme and apoenzyme. The second route revealed only lately, which results from uncoupled cytochrome P-450-catalyzed monooxygenase reactions, is yet to be clarified. Briefly, it consists in the fact that the hydrogen peroxide formed in the hemoprotein active center interacts with the enzyme-bound Fe2+, thereby generating hydroxyl radicals that bleach the heme and modify the apoenzyme. This mechanism operates with all the substrates and all cytochrome P-450 forms capable of catalyzing the partially coupled monooxygenase reactions proceeding with the formation of hydrogen peroxide as a by-product.
本文探讨了细胞色素P-450在催化周转过程中自我激活的可能机制。目前已知血红素蛋白失活的两条途径。第一条途径被许多作者广泛研究，在于形成能够修饰血红素和脱辅基酶的活性中间体。第二条途径是最近才发现的，它是由细胞色素P-450催化的单加氧酶反应解偶联导致的，目前尚待阐明。简而言之，它在于血红素蛋白活性中心形成的过氧化氢与酶结合的Fe2+相互作用，从而产生羟基自由基，使血红素褪色并修饰脱辅基酶。这种机制适用于所有底物以及所有能够催化以过氧化氢为副产物的部分偶联单加氧酶反应的细胞色素P-450形式。
