Related Experiment Video
Updated: Jul 8, 2026
08:15
Membrane Remodeling of Giant Vesicles in Response to Localized Calcium Ion Gradients
Published on: July 16, 2018
Giant vesicles as models to study the interactions between membranes and proteins
A Fischer1, T Oberholzer, P L Luisi
1Institut für Polymere, ETH Zentrum, Zürich, Switzerland.
Biochimica Et Biophysica Acta
|August 10, 2000
Summary
Giant vesicles (GVs) offer a more accurate model for cell membranes than conventional liposomes. These GVs exhibit unique permeability and protein-substrate interaction properties, suggesting membrane curvature influences bilayer characteristics.
Area of Science:
- Biochemistry
- Cell Biology
- Membrane Biophysics
Background:
- Polypeptide-membrane interactions are crucial in cell biochemistry.
- Liposomes serve as in vitro models for studying these interactions.
- Giant vesicles (GVs) offer a more cell-like model due to their larger size.
Purpose of the Study:
- To investigate the unique properties of giant vesicles (GVs) compared to conventional liposomes.
- To explore the permeability and protein-substrate interaction capabilities of GVs.
- To understand the influence of membrane curvature on bilayer properties.
Main Methods:
- Electroformation of giant vesicles (GVs) from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine.
- Assessing GV permeability to low molecular weight molecules like YO-PRO-1 and fluorescein diphosphate.
- Monitoring protein-membrane interactions using non-membrane proteins (DNases, RNases) and their substrates.
Main Results:
- GVs demonstrated permeability to specific small molecules, unlike conventional liposomes.
- External non-membrane proteins could interact with internal substrates within GVs.
- These effects were specific to GVs and absent in conventional liposomes, even after removal from the electroformation environment.
Conclusions:
- Giant vesicles exhibit distinct permeability and functional protein-membrane interaction properties compared to conventional liposomes.
- These differences suggest that membrane curvature, a characteristic of GVs, influences bilayer physico-chemical properties.
- The precise mechanism behind these curvature-induced effects requires further investigation.
More Related Videos
Related Concept Videos
01:18Membrane Domains
The membrane domains concentrate specific lipids and proteins at one place within the membrane, which helps in cell signaling, adhesion, and other critical cellular processes. These domains can differ in size, composition, function, and lifespan.
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
01:38Intralumenal Vesicles and Multivesicular Bodies
Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
01:33Overview of Secretory Vesicles
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
00:59COP Coated Vesicles
Membrane-enclosed structures called vesicles transport proteins and lipids across the cell. The vesicles derive their cargo from the plasma membrane, Golgi, ER, or endosome. Coated vesicles are spherical, protein-coated carriers with a 50–100 nm diameter that mediate bidirectional transport between the ER and the Golgi. The distribution of proteins between the ER and Golgi complex is dynamic and is maintained by different coated vesicles. Their formation is driven by the assembly of different...
00:59Mechanisms 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 cytoskeletal...
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
01:12Clathrin Coated Vesicles
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...