ABSTRACT
Protein–protein electron transfer is influenced by a host of important structural and dynamic factors. This chapter focuses on the events leading up to the formation of productive electron transfer complexes through rotational and translational diffusion, and influenced by predominantly electrostatic and steric forces. Four major topics are addressed: the role of electrostatic charge distribution in stabilizing individual electron transfer complexes; dynamics of protein–protein association by a diffusional mechanism; the possible existence of alternative docking geometries rather than a single complex through which electron transfer can occur; and the influence of protein flexibility and internal dynamics on an individual association complex. A treatment of the dynamics of associative encounters is of fundamental importance in the full modelling of protein electron transfer, and is amenable to study by the methodology called Brownian dynamics (BD). However, the BD method for simulation of electron transfer rates between metalloproteins as it is currently implemented has a number of shortcomings.
