Investigating the Bacillus Subtilis Membrane and Its Interactions with Antimicrobial Peptides

Monday, Jan. 12, 1-2 p.m.

CSF-1302

Hello Everyone,

You are warmly invited to attend the upcoming seminar on Monday, January 12^th , 2026. Please find the details below.

Investigating the Bacillus subtilis Membrane and its Interactions with Antimicrobial Peptides

Claire Langille

MSc Student

Department of Human Biosciences

January 12^th, 2026

1:00 p.m. – 2:00 p.m.

CSF-1302

The direct link for the meeting is:

https://mun.webex.com/mun/j.php?MTID=ma96857cfb234d296f6797cbef3f15f88

Abstract

Antibiotic resistant bacteria were responsible for more than one million deaths worldwide in 2019 alone, and this number is only projected to increase. Substitutes for traditional antibiotics must be investigated to address this global health crisis. One alternative is a group of peptides called antimicrobial peptides, or AMPs. AMPs are small, positively charged peptides that can target negatively charged bacterial cell membranes via electrostatic interactions. Many AMPs can target bacterial membranes for disruption while leaving host cells unharmed, but the mechanism underlying this selectively remains unclear. Our study aims to investigate how AMP selectivity is influenced by the lipid composition of bacterial membranes by focusing on Bacillus subtilis, a model Gram-positive bacterium. While B. subtilis is commonly used in laboratory settings, its specific lipid composition is not fully understood. Using mass spectrometry methods and shotgun lipidomics, we have identified the specific phospholipid composition of the membrane, which is made almost entirely of branched-chain phospholipids. The data collected via mass spectrometry was used to create a computational model of the B. subtilis membrane, using the Martini 3 forcefield and the Gromacs molecular dynamics package. Dynamic membrane properties were analyzed to ensure they agreed with published experimental data. Molecular dynamics simulations of AMPs interacting with the membrane model are underway, with a goal of uncovering the molecular basis of AMP selectivity with respect to the B. subtilis membrane. The data collected in this study provides foundations for further studies of B. subtilis and will identify AMP features that should be prioritized in next-generation antibiotic development.

All are welcome to attend. Please mark your calendars and join us for this exciting presentation.

Best regards,

Presented by Department of Human Biosciences

Event Listing 2026-01-12 13:00:00 2026-01-12 14:00:00 America/St_Johns Investigating the Bacillus Subtilis Membrane and Its Interactions with Antimicrobial Peptides Hello Everyone, You are warmly invited to attend the upcoming seminar on Monday, January 12th , 2026. Please find the details below. Investigating the Bacillus subtilis Membrane and its Interactions with Antimicrobial Peptides Claire Langille MSc Student Department of Human Biosciences January 12th, 2026 1:00 p.m. – 2:00 p.m. CSF-1302 The direct link for the meeting is: https://mun.webex.com/mun/j.php?MTID=ma96857cfb234d296f6797cbef3f15f88 Abstract Antibiotic resistant bacteria were responsible for more than one million deaths worldwide in 2019 alone, and this number is only projected to increase. Substitutes for traditional antibiotics must be investigated to address this global health crisis. One alternative is a group of peptides called antimicrobial peptides, or AMPs. AMPs are small, positively charged peptides that can target negatively charged bacterial cell membranes via electrostatic interactions. Many AMPs can target bacterial membranes for disruption while leaving host cells unharmed, but the mechanism underlying this selectively remains unclear. Our study aims to investigate how AMP selectivity is influenced by the lipid composition of bacterial membranes by focusing on Bacillus subtilis, a model Gram-positive bacterium. While B. subtilis is commonly used in laboratory settings, its specific lipid composition is not fully understood. Using mass spectrometry methods and shotgun lipidomics, we have identified the specific phospholipid composition of the membrane, which is made almost entirely of branched-chain phospholipids. The data collected via mass spectrometry was used to create a computational model of the B. subtilis membrane, using the Martini 3 forcefield and the Gromacs molecular dynamics package. Dynamic membrane properties were analyzed to ensure they agreed with published experimental data. Molecular dynamics simulations of AMPs interacting with the membrane model are underway, with a goal of uncovering the molecular basis of AMP selectivity with respect to the B. subtilis membrane. The data collected in this study provides foundations for further studies of B. subtilis and will identify AMP features that should be prioritized in next-generation antibiotic development. All are welcome to attend. Please mark your calendars and join us for this exciting presentation. Best regards, CSF-1302 Department of Human Biosciences