Structural Determinants of Redox Conduction Favor Robustness over Tunability in Microbial Cytochrome Nanowires.

ABSTRACT: Helical homopolymers of multiheme cytochromes catalyze biogeochemically significant electron transfers with a reported 10 ³ -fold variation in conductivity. Herein, classical molecular dynamics and hybrid quantum/classical molecular mechanics are used to elucidate the structural determinants of the redox potentials and conductivities of the tetra-, hexa-, and octaheme outer-membrane cytochromes E, S, and Z, respectively, from Geobacter sulfurreducens . Second-sphere electrostatic interactions acting on minimally polarized heme centers are found to regulate redox potentials over a computed 0.5-V range. However, the energetics of redox conduction are largely robust to the structural diversity: Single-step electronic couplings (⟨H _mn ⟩), reaction free energies , a

SUBMITTER: Guberman-Pfeffer MJ 

PROVIDER: S-EPMC9882360 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature