TIME RESOLVED TRYPTOPHAN FLUORESCENCE FROM CYTOCHROME B5

分子动力学模拟揭示了暴露的血红素边缘 在细胞色素的任何晶体或核磁共振结构中都没有观察到 B5.这种裂隙很可能在功能上对 认可氧化还原伙伴作为直接电子转移的媒介 对于一些综合体来说。为了研究唇裂呼吸的动力学 我们启动了单一色氨酸-22的稳态荧光研究。 丙烯酰胺猝灭单一色氨酸大鼠细胞色素b5和 用超快时间分辨技术检测了它的各种二硫键突变体 光谱学。为了探索推测的裂隙的动力学，一个 在表面放置了额外的色氨酸(S18W)。 野生型的寿命分布和各向异性衰变的比较 并且带有Trp-18的突变体可能提供关于移动性的新信息 位于蛋白质裂隙区域的蛋白质表面。

Molecular dynamic simulations reveal an exposed heme edge that has not been observed in any crystal or NMR structure of cytochrome b5. This cleft is likely to be of functional importance for recognition of a redox partner for mediating direct electron transfer for some complexes. In order to study dynamics of the cleft breathing we initiated a steady-state fluorescence study of single Trp-22. Acrylamide quenching of the single tryptophan rat cytochrome b5 and its various disufide mutants was examined by ultrafast time-resolved spectroscopy. In order to probe dynamics of the putative cleft, an additional tryptophan has been placed on the surface (S18W). Comparison of lifetime distribution and anisotropy decays of wild-type and mutant with Trp-18 may provide new information about mobility of the protein surface in the cleft region of the protein.