Related Experiment Video

Updated: Dec 19, 2025

Multifunctional, Micropipette-based Method for Incorporation And Stimulation of Bacterial Mechanosensitive Ion Channels in Droplet Interface Bilayers
09:54

Multifunctional, Micropipette-based Method for Incorporation And Stimulation of Bacterial Mechanosensitive Ion Channels in Droplet Interface Bilayers

Published on: November 19, 2015

11.1K

Effect of membrane potential on pore formation by the antimicrobial peptide magainin 2 in lipid bilayers

Md Mamun Or Rashid1, Md Mizanur Rahman Moghal1, Md Masum Billah1

  • 1Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan.

Biochimica Et Biophysica Acta. Biomembranes
|June 7, 2020
PubMed

Insights

Antimicrobial peptides (AMPs) cause membrane damage. This study shows that magainin 2 (Mag) forms pores more readily in lipid membranes with a negative membrane potential, due to increased peptide binding.

Area of Science:

  • Biophysics
  • Membrane Biology
  • Antimicrobial Peptides

Background:

  • The interaction of antimicrobial peptides (AMPs) with lipid bilayers is crucial for their function.
  • The influence of membrane potential on AMP-induced membrane damage is not fully understood.

Purpose of the Study:

  • To investigate the effect of membrane potential on pore formation by magainin 2 (Mag) in giant unilamellar vesicles (GUVs).
  • To determine how membrane potential influences the binding and activity of Mag.

Main Methods:

  • Studied pore formation by Mag in DOPG/DOPC GUVs under varying membrane potentials generated by K+ gradients.
  • Used fluorescent probes (calcein, CF-Mag, AF647) and confocal laser scanning microscopy (CLSM) to quantify permeation, peptide binding, and localization.

Main Results:

  • The rate of Mag-induced pore formation (k_p) increased with more negative membrane potentials.
  • Mag binding to the membrane, indicated by increased CF-Mag concentration, was enhanced at negative membrane potentials.
  • CF-Mag localized to the external leaflet of GUVs before pore formation.

Conclusions:

  • Increased surface concentration of Mag at negative membrane potentials is a primary driver for enhanced pore formation.
  • Membrane potential significantly modulates the interaction of magainin 2 with lipid membranes, affecting its pore-forming activity.
Keywords:
Antimicrobial peptidesGiant unilamellar vesiclesMagainin 2Membrane potentialPore formationSurface concentration

More Related Videos

Automated Lipid Bilayer Membrane Formation Using a Polydimethylsiloxane Thin Film08:23

Automated Lipid Bilayer Membrane Formation Using a Polydimethylsiloxane Thin Film

Published on: July 10, 2016

18.9K
A Liposome Membrane Permeability Assay for Investigating the Effects of Phosphatidylinositol Phosphate Groups on Membranotropic Action of Venom PLA210:31

A Liposome Membrane Permeability Assay for Investigating the Effects of Phosphatidylinositol Phosphate Groups on Membranotropic Action of Venom PLA2

Published on: September 26, 2025

318

Related Concept Videos

Mechanisms of Membrane Domain Formation00:59

Mechanisms of Membrane Domain Formation

Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.7K
Protein Diffusion in the Membrane01:24

Protein Diffusion in the Membrane

Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
5.3K
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
12.8K
Mechanisms of Membrane-bending01:15

Mechanisms of Membrane-bending

The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
3.2K
Pore Transport and Ion-Pair Transport01:17

Pore Transport and Ion-Pair Transport

Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited  but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
1.0K
Resting Membrane Potential01:24

Resting Membrane Potential

The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
20.9K