2 research outputs found
Amide neighbouring-group effects in peptides: phenylalanine as relay amino acid in long-distance electron transfer
In nature, proteins serve as media for longādistance electron transfer (ET) to carry out redox reactions in distant compartments. This ET occurs either by a singleāstep superexchange or through a multiāstep charge hopping process, which uses side chains of amino acids as stepping stones. In this study we demonstrate that Phe can act as a relay amino acid for longādistance electron hole transfer through peptides. The considerably increased susceptibility of the aromatic ring to oxidation is caused by the lone pairs of neighbouring amide carbonyl groups, which stabilise the Phe radical cation. This neighbouringāamideāgroup effect helps improve understanding of the mechanism of extracellular electron transfer through conductive protein filaments (pili) of anaerobic bacteria during mineral respiration