Melittin is the active component of bee venom and when injected releases histamine from mast cells and ruptures red blood cell corpuscles. This interaction is responsible for the initial pain and swelling that is associated with a bee sting. (Collison, 41) However, the properties that make melittin toxic can also be harnessed for therapeutic purposes. Melittin is a small protein containing 26 amino acids that comprises 50% of bee venom’s dry weight. (Collison, 40) It exists primarily in two distinct forms. In water it exists as a soluble folded tetramer, but can spontaneously rearrange into a monomeric alpha-helix under alkaline pH, high salt, high acid, or in high peptide concentration solutions. During the tetramer/monomeric alpha-helix rearrangement melittin can integrate itself into a cell’s lipid membrane. (Godballe, 172-183)
Mechanism of Melittin-Bilayer Interaction
The integration of melittin into a cell’s lipid membrane is what causes the rupturing of red blood cells during a bee sting. Melittin employs this conformational change and proceeds to destroy the cells around the site of injection. This method …show more content…
This means that melittin has a conformation orienting the hydrophobic side chains towards the inside of the helix while the hydrophilic chains orient themselves towards the outside of the bend. This configuration is what allows melittin to integrate itself into the bilayer in such a way that causes the hydrophobic portion of the molecule to become depressed into the nonpolar portion of a cellular membrane. This integration of melittin into only one side of the bilayer produces a surface area difference between the top and bottom layers which creates a wedge effect. This method of action is why melittin is classified as a “surface layer protein” and is the most likely mechanism used for lysis. (Godballe,
Mechanism of Melittin-Bilayer Interaction
The integration of melittin into a cell’s lipid membrane is what causes the rupturing of red blood cells during a bee sting. Melittin employs this conformational change and proceeds to destroy the cells around the site of injection. This method …show more content…
This means that melittin has a conformation orienting the hydrophobic side chains towards the inside of the helix while the hydrophilic chains orient themselves towards the outside of the bend. This configuration is what allows melittin to integrate itself into the bilayer in such a way that causes the hydrophobic portion of the molecule to become depressed into the nonpolar portion of a cellular membrane. This integration of melittin into only one side of the bilayer produces a surface area difference between the top and bottom layers which creates a wedge effect. This method of action is why melittin is classified as a “surface layer protein” and is the most likely mechanism used for lysis. (Godballe,