ELECTRON-TUNNELING PATHWAYS IN CYTOCHROME-C

被引：245

作者：

WUTTKE, DS ^{[1
]}

BJERRUM, MJ ^{[1
]}

WINKLER, JR ^{[1
]}

GRAY, HB ^{[1
]}

机构：

[1] CALTECH, BECKMAN INST, PASADENA, CA 91125 USA

来源：

SCIENCE | 1992年 / 256卷 / 5059期

关键词：

D O I：

10.1126/science.256.5059.1007

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Distant Fe2+-Ru3+ electronic couplings have been extracted from intramolecular electron-transfer rates in Ru(histidine(x)) (where X = 33, 39, 62, and 72) derivatives of cytochrome c. The couplings increase according to 62 (0.0060) < 72 (0.057) < 33 (0.097) < 39 (0.11 per wave numbers); however, this order is out of line with the histidine to heme edge-edge distances [62 (14.8) > 39 (12.3) > 33 (11.1) > 72 (8.4 angstroms)]. The rates (and the couplings) correlate with the lengths of sigma-tunneling pathways comprised of covalent bonds, hydrogen bonds, and through-space jumps from the histidines to the heme group. Space jumps greatly decrease couplings: One from Pro71 to Met80 extends the sigma-tunneling length of the His72 pathway by roughly 10 covalent-bond units.

引用

页码：1007 / 1009

页数：3