Related Experiment Video
Updated: Jul 11, 2026
10:07
High-throughput Measurement of Plasma Membrane Resealing Efficiency in Mammalian Cells
Published on: January 7, 2019
Conolysin-Mt: a conus peptide that disrupts cellular membranes
Jason S Biggs1, Yosef Rosenfeld, Yechiel Shai
1Department of Biology, University of Utah, Salt Lake City, Utah 84108, USA.
Biochemistry
|October 12, 2007
Summary
Researchers discovered conolysin-Mt, a novel peptide from Conus mustelinus venom, that effectively destroys cell membranes. This conopeptide shows potent hemolytic activity and a unique specificity for eukaryotic membranes.
Area of Science:
- Marine Biology
- Biochemistry
- Pharmacology
Background:
- Conus venoms contain numerous pharmacologically active peptides, primarily targeting ion channels.
- Existing knowledge of conopeptide mechanisms primarily focuses on ion channel interactions.
Purpose of the Study:
- To characterize a novel cytolytic peptide, conolysin-Mt, from Conus mustelinus venom.
- To expand the understanding of conopeptide mechanisms beyond ion channel modulation.
- To investigate the membrane interaction and lytic activity of conolysin-Mt.
Main Methods:
- Purification and characterization of conolysin-Mt, a 23-amino acid peptide.
- Assay of hemolytic activity on human erythrocytes.
- Permeabilization studies on prokaryotic (PE:PG) and eukaryotic (PC:cholesterol) model membranes.
- Determination of affinity constants (KA) for model membranes.
- Antimicrobial activity testing against Escherichia coli and Staphylococcus aureus.
Main Results:
- Conolysin-Mt exhibits potent hemolytic activity against human erythrocytes.
- The peptide effectively permeabilizes both prokaryotic and eukaryotic model membranes.
- Conolysin-Mt demonstrates specific affinity for eukaryotic membranes (KA = 3 ± 1 x 10^7 M⁻¹).
- Low antimicrobial activity was observed against E. coli (MIC > 50 μM) and S. aureus (MIC = 25–50 μM).
Conclusions:
- Conolysin-Mt represents a novel class of conopeptides that induce membrane destruction.
- The peptide's specificity for eukaryotic membranes distinguishes it from other cytolytic peptides like melittin.
- Conolysin-Mt offers a new avenue for exploring venom-derived peptides with potential therapeutic applications targeting cell membranes.
Related Concept Videos
01:19Translocation of Proteins into the Mitochondria
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
01:24Caspases
Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside cells.
01:29Tetanus
Tetanus is a life-threatening neurological disorder characterized by persistent muscle contractions and spastic paralysis. It is caused by Clostridium tetani, a motile, Gram-positive, rod-shaped, obligate anaerobe. These bacteria produce terminal endospores, giving them a distinctive “lollipop” or “tennis-racket” appearance. They thrive in anaerobic environments, such as those found in deep puncture wounds.Once introduced into the body, the spores germinate into vegetative cells. These cells...
01:22Botulism
Botulism is a life-threatening neuroparalytic condition caused by botulinum neurotoxin, which is produced by the bacterium Clostridium botulinum, a Gram-positive, spore-forming, obligate anaerobe.In adults, the toxin enters the body in different ways: in foodborne botulism, the preformed toxin is absorbed in the intestine. In wound botulism, spores grow in injured tissue and release the toxin into the blood. Infant botulism differs mechanistically from adult forms. In infants, botulism commonly...
01:12Bacterial Toxins
Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
01:26Fusion of Secretory Vesicles with the Plasma Membrane
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...