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 electron-transfer reactions in biological systems is proposed. We use the tight-binding model to describe the motion of one-electron in an array representing the system: donor (D), acceptor (A), and all other atoms that compose the protein. The matrix elements |T_DA|;² is evaluated at the estimated electron energy. The essential part of the method lies in the evaluation of the off-diagonal Green function 〈I|G|F〉 between the site I neighboring with the donor and the site F with the acceptor. 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. © 1994 John Wiley & Sons, Inc.