Shteinman A A
Institue of Chemical Physics, Chernogolovka, Russian Federation.
FEBS Lett. 1995 Mar 27;362(1):5-9. doi: 10.1016/0014-5793(95)00195-f.
The binuclear structure of the active center of methane monooxygenase plays a determining role in dioxygen activation and in selectivity and specificity of alkane oxidation with this enzyme. A new mechanism is suggested for binding and activation of O2, which involves side-on binding of O2-(2) to iron atoms followed by its conversion to the bis-mu-oxo complex considered as an alternative of ferryl in CH4 activation. This mechanism results in the sequence of the cleavage of the O-O bond of peroxide O/O2-instead of the opposite sequence O2-/O, which takes place in the case of heme monooxygenase cytochrome P-450. Therefore, in this case there is no necessity of the charge relay system [N.B. Gerber and S.G. Sligar, J. Am. Chem. Soc. 114 (1992) 8742] for the transformation of O2 to an active intermediate. The experiment for checking this hypothesis is suggested.
甲烷单加氧酶活性中心的双核结构在双加氧激活以及该酶对烷烃氧化的选择性和特异性方面起着决定性作用。本文提出了一种新的氧气结合和激活机制，该机制涉及O₂⁻²以侧基方式与铁原子结合，随后转化为双-μ-氧代复合物，该复合物被认为是甲烷激活中高价铁的替代物。这种机制导致过氧化物O/O₂⁻的O - O键断裂顺序与血红素单加氧酶细胞色素P - 450的情况相反，即O₂⁻/O顺序。因此，在这种情况下，无需电荷中继系统[N.B. 格伯和S.G. 斯利加，《美国化学会志》114 (1992) 8742]来将O₂转化为活性中间体。文中还提出了验证这一假设的实验。
