Electron tunneling in structurally engineered proteins

被引:30
作者
Gray, HB [1 ]
Winkler, JR [1 ]
机构
[1] CALTECH, Beckman Inst, Pasadena, CA 91125 USA
来源
JOURNAL OF ELECTROANALYTICAL CHEMISTRY | 1997年 / 438卷 / 1-2期
基金
美国国家科学基金会; 美国国家卫生研究院;
关键词
electron tunneling; proteins; electron transfer rate; decay constant;
D O I
10.1016/S0022-0728(96)05024-3
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Photosynthesis, respiration, nitrogen fixation, drug metabolism, DNA synthesis, and immune response are among the scores of biological processes that rely heavily on long-range (10 to 25 Angstrom) protein electron-transfer (ET) reactions. Semiclassical theory predicts that the rates of these reactions depend on the reaction driving force -Delta G degrees, a nuclear reorganization parameter lambda, and the electronic-coupling strength H-AB between reactants and products at the transition state: ET rates (k(ET)degrees) reach their maximum values when the nuclear factor is optimized (-Delta G degrees = lambda); these k(ET)degrees values are limited only by the strength (H-AB(2)) of the electronic interaction between the donor (D) and acceptor (A). Coupling-limited Cu+ to Ru3+ and Fe2+ to Ru3+ ET rates have been extracted from kinetic studies on several Ru-modified proteins. In azurin, a blue copper protein, the distant D/A pairs are relatively well coupled (k(ET)degrees decreases exponentially with R(Cu-Ru); the decay constant is 1.1 Angstrom(-1)). In contrast to the extended peptides found in azurin and other beta-sheet proteins, helical structures have tortuous covalent pathways owing to the curvature of the peptide backbone. The decay constants estimated from ET rates for D/A pairs separated by long sections of the alpha helix in myoglobin and the photosynthetic reaction center are between 1.25 and 1.6 Angstrom(-1). (C) 1997 Elsevier Science S.A.
引用
收藏
页码:43 / 47
页数:5
相关论文
共 38 条
[11]   NEW HAMILTONIAN MODEL FOR LONG-RANGE ELECTRONIC SUPEREXCHANGE IN COMPLEX MOLECULAR-STRUCTURES [J].
GRUSCHUS, JM ;
KUKI, A .
JOURNAL OF PHYSICAL CHEMISTRY, 1993, 97 (21) :5581-5593
[12]   MODELING ABINITIO NONBONDED INTERACTIONS FOR SIGMA-BOND, PI-BOND, AND LONE PAIR ORBITALS [J].
GRUSCHUS, JM ;
KUKI, A .
CHEMICAL PHYSICS LETTERS, 1992, 192 (2-3) :205-212
[13]   ELECTRON-TRANSFER BETWEEN BIOLOGICAL MOLECULES BY THERMALLY ACTIVATED TUNNELING [J].
HOPFIELD, JJ .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1974, 71 (09) :3640-3644
[14]   STRUCTURE AT 2.8-ANGSTROM RESOLUTION OF CYTOCHROME-C-OXIDASE FROM PARACOCCUS-DENITRIFICANS [J].
IWATA, S ;
OSTERMEIER, C ;
LUDWIG, B ;
MICHEL, H .
NATURE, 1995, 376 (6542) :660-669
[15]  
KARPISHIN TB, UNPUB
[16]   Electron tunneling in proteins: Role of the intervening medium [J].
Langen, R ;
Colon, JL ;
Casimiro, DR ;
Karpishin, TB ;
Winkler, JR ;
Gray, HB .
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY, 1996, 1 (03) :221-225
[17]   ELECTRON-TUNNELING IN PROTEINS - COUPLING THROUGH A BETA-STRAND [J].
LANGEN, R ;
CHANG, IJ ;
GERMANAS, JP ;
RICHARDS, JH ;
WINKLER, JR ;
GRAY, HB .
SCIENCE, 1995, 268 (5218) :1733-1735
[18]  
Langen R, 1995, THESIS CALTECH
[19]   ABINITIO STUDIES OF ELECTRON-TRANSFER - PATHWAY ANALYSIS OF EFFECTIVE TRANSFER INTEGRALS [J].
LIANG, CX ;
NEWTON, MD .
JOURNAL OF PHYSICAL CHEMISTRY, 1992, 96 (07) :2855-2866
[20]   ELECTRON TRANSFERS IN CHEMISTRY AND BIOLOGY [J].
MARCUS, RA ;
SUTIN, N .
BIOCHIMICA ET BIOPHYSICA ACTA, 1985, 811 (03) :265-322