Nanosecond Photoreduction of Cytochrome P450cam by Channel-Specific Ru-diimine Electron Tunneling Wires
作者:Alexander R. Dunn、Ivan J. Dmochowski、Jay R. Winkler、Harry B. Gray
DOI:10.1021/ja0294111
日期:2003.10.1
substrate access channel. With Ru-F(8)bp wires, redox reactions can be triggered on the nanosecond time scale. Ru-wire 2, which ligates the heme iron, shows a small amount of transient heme photoreduction (ca. 30%), whereas the transient photoreduction yield for 4 is 76%. Forward ET with 4 occurs in roughly 40 ns (k(f) = 2.8 x 10(7) s(-)(1)), and back ET (Fe(II) --> Ru(III), k(b) approximately 1.7 x 10(8) s(-)(1))
我们报告了旨在与细胞色素 p450cam (CYP101) 结合的 Ru-二亚胺复合物的合成和表征。敏化剂核心具有 [Ru(L(2))L'](2+) 结构,其中 L' 是连接 4,4'-二甲基联吡啶和酶底物(金刚烷)的全氟联苯桥 (F(8)bp) 、F(8)bp-Ad)、血红素配体(咪唑、F(8)bp-Im)或 F(F(9)bp)。通过用 4,4',5,5'-四甲基联吡啶 (tmRu) 替换辅助 2,2'-联吡啶配体来改变电子转移 (ET) 驱动力 (-deltaG 度)。四种复合物都与 p450cam 紧密结合:Ru-F(8)bp-Ad (1, K(d) = 0.077 microM);Ru-F(8)bp-Im (2, K(d) = 3.7 microM); tmRu-F(9)bp (3, K(d) = 2.1 microM); 和 tmRu-F(8)bp-Im (4, K(d) = 0