Superexchange coupling and electron transfer in globular proteins via polaron excitations.
The polaron approach is used to treat long-range electron transfers between globular proteins. A rate expression for the polaron transfer model is given along with a description of appropriate conditions for its use. Assuming that electrons transfer via a superexchange coupling due to a polaron excitation, we have estimated the distance dependence of the rate constant for the self-exchange reactions between globular proteins in solutions. The distance dependence of the polaron coupling and solvent reorganization energy are provided as a basis for understanding and interpreting a long-range electron transfer experiment. The difficulties and problems of the polaron treatment of long-range electron transfers are discussed, and suggestions for new experiments are made.
Russian Academy of Sciences, Institute of Mathematical Problems of Biology, Pushchino, Moscow Region, 142292.
G N
GN
Chuev
V D
VD
Lakhno
M N
MN
Ustitnin
Cytochrome; electron transfer; excited transition state; globular protein; polaron; superexchange coupling