IMSc Webinar

Understanding the mechanical response of bacterial cell walls and cell membranes against antimicrobial agents

Garima Rani

TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad

In this thesis, we employ biophysical methods to study the design principles of the bacterial cell wall and to study the efficacy of biomimetic methacrylate polymers as antimicrobial agents. Specifically, in the first part of the thesis, we explore the design principles underpinning the viability of the cell wall of bacteria, which is primarily composed of the peptidoglycan (PG) network, a mesh of relatively long and stiff glycan chains, cross-linked intermittently by flexible peptides. We examine the molecular level architecture of the PG mesh and its role in enhancing the toughness or the resistance to crack propagation, of the cell wall. We also investigate the ef- fect of variability in the elastic properties of the PG mesh on its bulk mechanical response, by studying an appropriately modelled spring system using theoretical methods and simulations. In the second part of the thesis, we study the confor-mational landscape, aggregation dynamics and interactions with model bacterial membrane of biomimetic methacrylate ternary antimicrobial polymers (AMPolys), utilizing detailed atomistic molecular dynamics simulations. Our aim here is to go beyond the traditional binary composition design, constituting hydrophobic and charged cationic groups, of such AMPolys, by including additional functional groups in order to better optimize their antimicrobial action. We specifically examine the role played by neutral polar groups in influencing the aggregation dynamics of such polymers in solution phase and study their membrane-interactions in depth. Further, we also investigate the conformational landscape of AMPolys that have anionic functional groups as constituents, with particular focus on probing the formation of salt bridges and their role in determining the conformational dynamics of such polymers.

*********************************************
Google Meet Link: meet.google.com/qzr-rpeo-nyn
**********************************************