Research

Life Sciences & Biotechnology

Title :

DNA duplex stability: Effect of salt concentration and cation valency

Area of research :

Life Sciences & Biotechnology

Principal Investigator :

Prof. Navin Singh, Birla Institute Of Technology And Science (BITS), Pilani, Rajasthan

Timeline Start Year :

2023

Timeline End Year :

2026

Contact info :

Equipments :

Details

Executive Summary :

Deoxyribonucleic acid (DNA) is a crucial biological macromolecule that stores genetic information in living organisms. It consists of repeating units called nucleotides, which are composed of sugar, phosphate, and bases (Adenine, Thymine, Guanine, or Cytosine). The double-helical structure of DNA is formed through pairing between bases on complementary strands, which can be disrupted during transcription and replication processes. This process is known as melting, denaturation, or unzipping of DNA. The study of DNA molecules is significant from physiological and technological perspectives. Intracellular sodium triggers cell division, and the presence of salt in the solution plays a pivotal role in many biological activities. The two strands of DNA carry a negative charge due to the phosphate group, so they can only make a stable pair in the presence of cations. These cations nullify the force of Coloumbic repulsion between the two strands. Primary salts generated inside the cell are $NaCl$ and $MgCl_2$, which release $Na^+$ and $Mg^{2+}$ when reacting with water. Chlorine rearranges itself in the form of hydrogen chloride ($HCl$), acting as electrostatic screening agents due to an attractive force between the positive ions and the negative strands. Theoretical studies on DNA phase transition often focus on the constant buffer or salt concentration. However, several studies have explored how ions interact with DNA and modulate its structure and interactions. The theoretical description is based on the standard Peyrard Bishop Dauxois (PBD) model, which has been used to study thermal and mechanical unzipping of the DNA molecule.

Total Budget (INR):

28,12,497

Organizations involved