Charge transfer in duplex DNA containing mismatch

Applications of biomaterials to liquid crystals

Nowadays, chemically synthesized proteins and peptides are attractive building blocks and have potential in many important applications as biomaterials. In this review, applications of biomaterials to thermotropic liquid crystals are discussed. The review covers the improvement of the performance of liquid crystal displays using liquid crystal physical gels consisting of a liquid crystal and amino acid-based gelators, and also new functionalization of liquid crystals. Moreover, the influence of DNA, which is one of the more attractive biomaterials, dispersed in thermotropic liquid crystals and its potential use in the liquid crystal industry is described. In addition, we found interesting results during electrooptical measurements of liquid crystals doped with DNA, and explain them from the point of view of biological applications. These recent approaches suggest that these biomaterials may be applicable in the electronic device industry and should be considered as an interesting material with their physical properties having the potential to create or refine an industrial product.

Quantum transport anomalies in DNA containing mispairs

The effect of mispairs on charge transport in DNA of sequence (GC)(TA)(N)(GC)(3) connected to platinum electrodes is studied using the tight-binding model. With parameters derived from an ab initio density functional result, we calculate the current versus bias voltage for DNA with and without a mispair and for different numbers of (TA) basepairs N between the single and triple (GC) basepairs. The current decays exponentially with N under low bias but reaches a minimum under high bias when a multichannel transport mechanism is established. A (GA) mispair substituting a (TA) basepair near the middle of the (TA)(N) sequence usually enhances the current by one order due to its low ionization energy but may decrease the current significantly when an established multichannel mechanism is broken.

A combined DFT/Green's function study on electrical conductivity through DNA duplex between Au electrodes

Electrical conducting properties of DNA duplexes sandwiched between Au electrodes have been investigated by use of first-principles molecular simulation based on DFT and Green's function to elucidate the origin of their base sequence dependence. The theoretically simulated effects of DNA base sequence on the electrical conducting properties are in qualitative agreement with experiment. The HOMOs localized on Guanine bases have the major contribution to the electrical conductivity through DNA duplexes.

Kinetics of charge transfer in DNA containing a mismatch

Charge transfer (CT) in DNA offers a unique approach for the detection of a single-base mismatch in a DNA molecule. While the single-base mismatch would significantly affect the CT in DNA, the kinetic basis for the drastic decrease in the CT efficiency through DNA containing mismatches still remains unclear. Recently, we determined the rate constants of the CT through the fully matched DNA, and we can now estimate the CT rate constant for a certain fully matched sequence. We assumed that further elucidating of the kinetics in mismatched sequences can lead to the discrimination of the DNA single-base mismatch based on the kinetics. In this study, we investigated the detailed kinetics of the CT through DNA containing mismatches and tried to discriminate a mismatch sequence based on the kinetics of the CT in DNA containing a mismatch.