Electron transfer in peptides

Abstract

In this review, we discuss the factors that influence electron transfer in peptides. We summarize experimental results from solution and surface studies and highlight the ongoing debate on the mechanistic aspects of this fundamental reaction. Here, we provide a balanced approach that remains unbiased and does not favor one mechanistic view over another. Support for a putative hopping mechanism in which an electron transfers in a stepwise manner is contrasted with experimental results that support electron tunneling or even some form of ballistic transfer or a pathway transfer for an electron between donor and acceptor sites. In some cases, experimental evidence suggests that a change in the electron transfer mechanism occurs as a result of donor-acceptor separation. However, this common understanding of the switch between tunneling and hopping as a function of chain length is not sufficient for explaining electron transfer in peptides. Apart from chain length, several other factors such as the extent of the secondary structure, backbone conformation, dipole orientation, the presence of special amino acids, hydrogen bonding, and the dynamic properties of a peptide also influence the rate and mode of electron transfer in peptides. Electron transfer plays a key role in physical, chemical and biological systems, so its control is a fundamental task in bioelectrochemical systems, the design of peptide based sensors and molecular junctions. Therefore, this topic is at the heart of a number of biological and technological processes and thus remains of vital interest.

Improvement of catalytic performance of lignin peroxidase for the enhanced degradation of lignocellulose biomass based on the imbedded electron-relay in long-range electron transfer route

“…Without the presence of aromatic amino acids such as Phe or Tyr or Trp, the gap between HOMO and LUMO levels do not appear to facile a transport of electrons [19]. For example, the oxidation of Cu I by electronically excited Re I is 100-fold faster than single-step ET due to the transient oxidation of W122, which was confirmed in case of azurin protein from Pseudomonas aeruginosa [20].…”

Detecting Electron Transport of Amino Acids by Using Conductance Measurement

“…Understanding the electron transport of biomolecules, including peptides, DNA, and RNA, has received much attention for its relation to daily life activities and potential applications in molecular devices [1,2,3,4,5,6]. Such electron transport has been proved to play an important role in the function of metabolic cycles, enzymatic processes, photosynthesis, DNA damage, and so on [1,3,7,8,9].…”

“…Such electron transport has been proved to play an important role in the function of metabolic cycles, enzymatic processes, photosynthesis, DNA damage, and so on [1,3,7,8,9]. …”

“…Much attention has been paid to the electron transport of peptides, which join electron acceptors and donors with each other and can contribute to the redox reaction between them [3]. Electrochemical methods or scanning tunneling microscopes (STMs) have been used to explore the electron transport properties of peptides, as well as the effect of length, hydrogen bonding, molecular dipole moment, electric field, metal ion binding, and pH on the electrical characterization of peptides [1,3,10,11,12].…”

Mechanically Controlled Electron Transfer in a Single-Polypeptide Transistor

“…Atomic force microscopy and scanning tunneling microscopy as techniques have greatly contributed to the investigation of protein electron transmission204445. Peptide ET seems to be mainly controlled by the sequence of the peptide and its secondary structure rather than chain length1416272946. The regular H-bonds between the main-chain N and O atoms within the secondary structures of peptides are expected to function as ET pathways2729474849.…”