ADENOSYLCOBALAMIN COFACTOR

核糖核苷三磷酸还原酶(RTPR) 莱氏乳杆菌此前已被证明能催化 ADOCbl的碳-钴键的均溶裂解，以及 由此产生的顺磁性物种的特征是 冷冻猝灭电子顺磁共振波谱(OrmeJohnson，1974)。模拟 X-和Q-带EPR谱模拟该自由基中间体为硫基 通过电子-电子交换与CoB(II)丙胺偶联的自由基， 偶极相互作用产生了与在两种情况下获得的光谱合理的拟合 微波频率(Gerfen，1997)。使用以下任一选项的模拟 单自旋模型或含钴(II)丙胺偶联有机化合物的模型 激进分子则不会。这为硫基自由基提供了支持 这个系统中的中间人。

The ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii has previously been shown to catalyze the homolytic cleavage of the carbon-cobalt bond of AdoCbl, and the resulting paramagnetic species has been characterized by rapid freeze-quench EPR spectroscopy (OrmeJohnson, 1974). Simulations of X-and Q-band EPR spectra modeling this radical intermediate as a thiyl radical coupled to cob(II)alamin by electron-electron exchange and dipolar interactions yield reasonable fits to spectra obtained at both microwave frequencies (Gerfen, 1997). Simulations that employ either a single-spin model or one with cob(II)alamin coupled to an organic radical do not. This provides support for a thiyl radical intermediate in this system.