Molecular Basis of Coupled Protein and Electron Transfer Dynamics of Cytochrome c in Biomimetic Complexes

摘要: Direct electron transfer (ET) of redox proteins immobilized on biomimetic or biocompatible electrodes represents an active field fundamental and applied research. In this context, several groups have reported for a variety unexpected distance dependencies the ET rate, whose origin remains largely speculative controversial, but appears to be quite general phenomenon. Here we employed molecular dynamics (MD) simulations pathway analyses study properties cytochrome c (Cyt) electrostatically Au coated by carboxyl-terminated alkylthiols. The MD concomitant binding energy calculations allow identification preferred configurations oxidized reduced Cyt which are established via different lysine residues and, thus, correspond orientations dipole moments. Calculations electronic coupling matrices various Cyt/self-assembled monolayer (SAM) complexes indicate that thermodynamically protein do not coincide with optimum coupling. These findings demonstrate is controlled interplay between tunneling probabilities. Protein exerts two level tuning reorientation (coarse) low amplitude thermal fluctuations (fine). Upon operating support as electrode, electric-field-dependent alignment moment becomes additional determinant thus overall rate. present results provide consistent description previous (spectro)electrochemical data conclusions concerning in physiological complexes.