scholarly journals Trapping and transport of charges in DNA by mobile discrete breathers

2018 ◽  
Vol 13 (1) ◽  
pp. 1-12 ◽  
Author(s):  
A.P. Chetverikov ◽  
K.S. Sergeev ◽  
V.D. Lakhno
Keyword(s):  
Numerical Simulation ◽  
Wave Function ◽  
Charged Particle ◽  
Electric Field ◽  
External Electric Field ◽  
Base Pair ◽  
Quasi Particle ◽  
Dna Molecule ◽  
Discrete Breathers

Numerical simulation of trapping and transport of a charged particle (electron or hole) by mobile discrete breathes (mobile DB, MDB) in DNA molecule has been provided. Mobile DBs have been excited by disturbance of displacements or velocities of adjacent nucleotide pairs dislocated near one of fixed ends of the molecule. It is shown that effective forming of a stable quasi-particle “MDB + electron” occurs when a few of nucleotide pairs at the end of DNA are excited. Breathes may be excited by disturbances of displacements and velocities directed both to axis and from axis of the molecule. A wave function of an electron must be located initially in a region of disturbance of the molecule. It has been found that a metastable quasi-particle may be transported at a distance up to 200 of a rise per base pair. The mechanism of transport of a charged particle presented is not in need of an external electric field and may be considered as an alternative one to the polaronic mechanism.

External electric field promotes proton transfer in the radical cation of adenine–thymine

2016 ◽  
Vol 30 (21) ◽  
pp. 1650276 ◽  
Author(s):  
Guiqing Zhang ◽  
Shijie Xie
Keyword(s):  
Electric Field ◽  
Proton Transfer ◽  
External Electric Field ◽  
Radical Cation ◽  
Base Pair ◽  
Low Temperatures ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Base Pairs ◽  
Adenine Thymine

According to [Formula: see text] measurements, it has been predicted that proton transfer would not occur in the radical cation of adenine–thymine (A:T). However, recent theoretical calculations indicate that proton transfer takes place in the base pair in water below the room temperature. We have performed simulations of proton transfer in the cation of B-DNA stack composed of 10 A:T base pairs in water from 20 K to 300 K. Proton transfer occurs below the room temperature, meanwhile it could also be observed at the room temperature under the external electric field. Another case that interests us is that proton transfer bounces back after [Formula: see text][Formula: see text]300 fs from the appearance of proton transfer at low temperatures.

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