Alladi Ramakrishnan Hall

Bridging induced coil-to-globule transitions in polymers

Hitesh Garg

IMSc, Chennai

Macromolecules or polymers are generally found themselves in crowded environments. The interior of a cell has a high concentration of macromolecules, typically constituting 20-30% of the total volume of a cell. Crowders play an important role in what is known as the coil-to-globule (C-G) transition of macromolecules, which is crucial for the functioning of biomacromolecules such as RNA, DNA, and proteins. The C-G transition can occur due to various reasons and phenomena, including solvent quality, co-non-solvency, temperature-mediated changes, depletion effect, etc. In this work, we studied the C-G transition occurring due to bridging interactions, where crowders act as bridges or glues between monomers to induce collapse. We performed extensive coarse-grained molecular dynamics simulations to investigate the phase diagram of both neutral and charged polymers in the presence of attractive crowders. We also shed light on the effects of crowder-crowder interactions, density, valency of counterions, and the size of crowders on such transitions.