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BP: Fachverband Biologische Physik
BP 6: Bacterial Biophysics I
BP 6.8: Talk
Monday, March 18, 2024, 17:15–17:30, H 1028
Using simulations to investigate the mechanical properties of peptidoglycan — •Marco Mauri1, Abimbola F. Adedeji Olulana2, Jamie K Hobbs2, Sheila Hoshyaripour1, and Rosalind J Allen1 — 1FSU Jena - Balance of the Microverse — 2University of Sheffield
In bacteria, the peptidoglycan (PG) cell wall consists of a mesh of glycan strands crosslinked by short peptides. PG counteracts the internal turgor pressure and its integrity is necessary to prevent cell lysis; indeed, many antibiotics target PG synthesis. The mechanical properties of the PG mesh are important for understanding the biophysics of cell growth, cell shape and antibiotic action: yet these properties are hard to measure experimentally.
Here, we present a coarse-grained molecular simulation model for the PG mesh in Gram negative bacteria such as E. coli. Inspired by previous works, we model PG as a network of beads and springs governed by a system of overdamped Langevin equations. However, our model incorporates real PG configurations, informed by AFM and biochemical measurements.
We use dynamical simulations to study how a patch of PG responds to biochemical perturbations. We predict the mechanical effects of antibiotic action via uncontrolled hydrolase enzymes, and explore the role of biophysical properties of the mesh, such as connectivity, on mechanical stability. Our work provides a connection between the molecular-scale PG configuration and the macro-scale mechanical properties of the cell wall.
Keywords: peptidoglycan; molecular simulation; antibiotic; cell wall; AFM