EVALUATION OF ELECTRONIC MATRIX-ELEMENTS OF LONG-RANGE ELECTRON-TRANSFER IN PROTEINS BY THE RECURSIVE RESIDUE GENERATION METHOD

An efficient method for calculating electronic matrix elements for ele ctron-transfer reactions in biological systems is proposed. We use the tight-binding model to describe the motion of one-electron in an arra y representing the system: donor (D), acceptor (A), and all other atom s that compose the protein. The matrix elements \T-DA\(2) is evaluated at the estimated electron energy. The essential part of the method li es in the evaluation of the off-diagonal Green function (I\G\F) betwee n the site I neighboring with the donor and the site F with the accept or. The recursive residue generation method is used to evaluate (I\G\F ). As an application, these matrix elements in metal-labeled myoglobin are calculated and the results are compared with those evaluated with the renormalized-perturbation-expansion approach. (C) 1994 John Wiley & Sons, Inc.