An understanding of how electrons tunnel long distances through organic media of proteins is crucial for the characterization of many biological processes, such as photosynthesis and respiration. A broad long-range goal of the proposed research is the development of a detailed quantum mechanical picture of long-distance electron transfer reactions in complex molecular systems that involved proteins and DNA. In order to achieve this goal, computer simulations, comparison with experimental data, and systematic theoretical analysis of the dynamics of photoinduced electron transfer reactions will be carried out for a variety of novel complex molecular systems that recently have been studied experimentally. In these systems, two transition metal complexes, donor and acceptor in the reaction, are separated by a large biological molecule, such as protein or DNA, that mediates a photoinduced electron transfer reaction. Specifically, the role of inelastic tunneling, symmetry effects of the donor and acceptor states, and interplay between structural and dynamical aspects of the biological tunneling will be investigated. Systems that will be studied include modified cytochromes, such as Ru(bpy)2im(his X)-cyt-c, azurin, myoglobin, and some other metalloproteins in which a Ru complex is bound to genetically engineered histidines on the surface of the protein; similarly, variable-length DNA helices containing a bound Ru-complex will be studied theoretically. Electron transfer properties of the pi-orbital system of the complex will be investigated. The DNA and protein complexes will be used to study the distance, as well as the structure, and base pair sequence dependence of intramolecular charge transfer rates. The proposed research will provide a quantitative understanding of how structure and dynamics of biological molecules controls charge transfer at the most fundamental quantum mechanical level.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29GM054052-02
Application #
2415354
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Project Start
1996-05-01
Project End
2001-04-30
Budget Start
1997-05-01
Budget End
1998-04-30
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of California Davis
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Stuchebrukhov, Alexei A (2018) Redox-Driven Proton Pumps of the Respiratory Chain. Biophys J 115:830-840
Hagras, Muhammad A; Stuchebrukhov, Alexei A (2016) Novel Inhibitors for a Novel Binding Site in Respiratory Complex III. J Phys Chem B 120:2701-8
Samudio, Benjamin M; Couch, Vernon; Stuchebrukhov, Alexei A (2016) Monte Carlo Simulations of Glu-242 in Cytochrome c Oxidase. J Phys Chem B 120:2095-105
Stuchebrukhov, Alexei (2016) Tunneling Time and the Breakdown of Born-Oppenheimer Approximation. J Phys Chem B 120:1408-17
Hagras, Muhammad A; Stuchebrukhov, Alexei A (2016) Internal switches modulating electron tunneling currents in respiratory complex III. Biochim Biophys Acta 1857:749-58
Morozenko, A; Stuchebrukhov, A A (2016) Dowser++, a new method of hydrating protein structures. Proteins 84:1347-57
Hagras, Muhammad A; Hayashi, Tomoyuki; Stuchebrukhov, Alexei A (2015) Quantum Calculations of Electron Tunneling in Respiratory Complex III. J Phys Chem B 119:14637-51
Hagras, Muhammad A; Stuchebrukhov, Alexei A (2015) Transition Flux Formula for the Electronic Coupling Matrix Element. J Phys Chem B 119:7712-21
Leontyev, Igor V; Stuchebrukhov, Alexei A (2014) Polarizable molecular interactions in condensed phase and their equivalent nonpolarizable models. J Chem Phys 141:014103
Medvedev, E S; Stuchebrukhov, A A (2014) Mechanisms of generation of local ?pH in mitochondria and bacteria. Biochemistry (Mosc) 79:425-34

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