Distal Charge Transport in Peptides

Biological systems often transport charges and reactive processes over substantial distances. Traditional models of chemical kinetics generally do not describe such extreme distal processes. In this Review, an atomistic model for a distal transport of information, which was specifically developed for peptides, is considered. Chemical reactivity is taken as the result of distal effects based on two‐step bifunctional kinetics involving unique, very rapid motional properties of peptides in the subpicosecond regime. The bifunctional model suggests highly efficient transport of charge and reactivity in an isolated peptide over a substantial distance; conversely, a very low efficiency in a water environment was found. The model suggests ultrafast transport of charge and reactivity over substantial molecular distances in a peptide environment. Many such domains can be active in a protein. Far‐reaching consequences: Charge transfer in peptides and proteins often leads to reactivity at a distal point. This process involves very fast facile molecular motions on a time scale of 100 fs, which is unique to peptides. The principal motions are found to be the dihedral motions between neighboring amino acids around the Ramachandran angles (ψ and ϕ in the model peptide; green C, gray H, blue N, red O).