Magnetic Fields Facilitate DNA-Mediated Charge Transport

Programmable Biomolecule-Mediated Processors

Programmable biomolecule-mediated computing is a new computing paradigm as compared to contemporary electronic computing. It employs nucleic acids and analogous biomolecular structures as information-storing and -processing substrates to tackle computational problems. It is of great significance to investigate the various issues of programmable biomolecule-mediated processors that are capable of automatically processing, storing, and displaying information. This Perspective provides several conceptual designs of programmable biomolecule-mediated processors and provides some insights into potential future research directions for programmable biomolecule-mediated processors.

Trends to store digital data in DNA: an overview

There has been an ascending growth in the capacity of information being generated. The increased production of data in turn has put forward other challenges as well thus, and there is the need to store this information and not only to store it but also to retain it for a prolonged time period. The reliance on DNA as a dense storage medium with high storage capacity and its ability to withstand extreme environmental conditions has increased over the past few years. There have been developments in reading and writing different forms of data on DNA, codes for encrypting data and using DNA as a way of secret writing leading towards new styles like stenography and cryptography. The article outlines different methods adopted for storing digital data on DNA with pros and cons of each method that has been applied plus the advantages and limitations of using DNA as a storage medium.

A Molecular Dynamics-Quantum Mechanics Theoretical Study of DNA-Mediated Charge Transport in Hydrated Ionic Liquids

Charge transport (CT) through biomolecules is of high significance in the research fields of biology, nanotechnology, and molecular devices. Inspired by our previous work that showed the binding of ionic liquid (IL) facilitated charge transport in duplex DNA, in silico simulation is a useful means to understand the microscopic mechanism of the facilitation phenomenon. Here molecular dynamics simulations (MD) of duplex DNA in water and hydrated ionic liquids were employed to explore the helical parameters. Principal component analysis was further applied to capture the subtle conformational changes of helical DNA upon different environmental impacts. Sequentially, CT rates were calculated by a QM/MM simulation of the flickering resonance model based upon MD trajectories. Herein, MD simulation illustrated that the binding of ionic liquids can restrain dynamic conformation and lower the on-site energy of the DNA base. Confined movement among the adjacent base pairs was highly related to the increase of electronic coupling among base pairs, which may lead DNA to a CT facilitated state. Sequentially combining MD and QM/MM analysis, the rational correlations among the binding modes, the conformational changes, and CT rates illustrated the facilitation effects from hydrated IL on DNA CT and supported a conformational-gating mechanism.

Hole Transport in A-form DNA/RNA Hybrid Duplexes

DNA/RNA hybrid duplexes are prevalent in many cellular functions and are an attractive target form for electrochemical biosensing and electric nanodevice. However the electronic conductivities of DNA/RNA hybrid duplex remain relatively unexplored and limited further technological applications. Here cyclopropyl-modified deoxyribose- and ribose-adenosines were developed to explore hole transport (HT) in both DNA duplex and DNA/RNA hybrids by probing the transient hole occupancies on adenine tracts. HT yields through both B-form and A-form double helixes displayed similar shallow distance dependence, although the HT yields of DNA/RNA hybrid duplexes were lower than those of DNA duplexes. The lack of oscillatory periods and direction dependence in HT through both helixes implied efficient hole propagation can be achieved via the hole delocalization and coherent HT over adenine tracts, regardless of the structural variations.