Related Experiment Video
Updated: Jun 26, 2026
11:20
Fabrication and Visualization of Capillary Bridges in Slit Pore Geometry
Published on: January 9, 2014
Transbilayer pores induced by thickness fluctuations.
Liviu Movileanu1, Dumitru Popescu, Stelian Ion
1Department of Physics, Syracuse University, 201 Physics Building, Syracuse, NY 13244-1130, USA. lmovilea@physics.syr.edu
Bulletin of Mathematical Biology
|December 7, 2006
Summary
Collective thermal movements (CTM) in lipid bilayers can create transbilayer stochastic pores. This study models pore formation, revealing stable and unstable pore types influenced by lipid properties and environmental factors.
Area of Science:
- Biophysics
- Materials Science
- Physical Chemistry
Background:
- Phospholipids in bilayer lipid membranes (BLMs) exhibit thermal fluctuations.
- Intermolecular interactions convert individual motions into collective thermal movements (CTM).
Purpose of the Study:
- To demonstrate the generation of transbilayer stochastic pores via CTM.
- To estimate pore radius and energetic requirements for pore formation in BLMs.
Main Methods:
- Application of elastic theory of continuous media, adapted from smectic-A liquid crystals.
- Modeling of thermally-induced transbilayer pore formation and stability.
Main Results:
- Three types of pores identified: open/stable, open/unstable, and closed.
- Two open and stable pores, with equal generation probability, are common.
- Pore characteristics depend on hydrophobic thickness, headgroup size, temperature, surface tension, and elastic compression.
Conclusions:
- Collective thermal movements are a viable mechanism for transbilayer pore formation in lipid bilayers.
- Lipid properties and environmental conditions significantly influence pore characteristics and stability.
Related Concept Videos
01:35Asymmetric Lipid Bilayer
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
01:24Protein 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...
01:25Aquaporins
Aquaporins or AQPs are a family of integral membrane proteins whose primary function is to transport water, while some called aquaglyceroporins also transport glycerol. In addition, aquaporins have also been suspected to be involved in transporting volatile substances, such as carbon dioxide and ammonia, across membranes. Such AQPs that act as gas channels are often highly expressed in cells involved in the gaseous exchange, such as red blood cells, epithelial cells, and pulmonary capillaries.
01:19Membrane Asymmetry Regulating Transporters
Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
01:09Multi-pass Transmembrane Proteins and β-barrels
In multi-pass transmembrane proteins, the polypeptide chain crosses the membrane more than once. The transmembrane polypeptide chain either forms an α-helix or β-strand structure. α-Helix containing multi-pass transmembrane proteins are ubiquitous, whereas β-strand containing ones are mainly found in gram-negative bacteria, mitochondria, and chloroplasts.
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
01:17Pore 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 microscopic...
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 microscopic...