Chemistry:Melittin
| Melittin | |||||||||
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 Melittin | |||||||||
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| Symbol | Melittin | ||||||||
| Pfam | PF01372 | ||||||||
| InterPro | IPR002116 | ||||||||
| SCOP2 | 2mlt / SCOPe / SUPFAM | ||||||||
| TCDB | 1.C.18 | ||||||||
| OPM superfamily | 151 | ||||||||
| OPM protein | 2mlt | ||||||||
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3D model (JSmol)
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| ChemSpider | |
| MeSH | Melitten |
PubChem CID
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| Properties | |
| C131H229N39O31 | |
| Molar mass | 2846.46266 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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| Infobox references | |
Melittin is the main component (40–60% of the dry weight) and the major pain-producing substance of honeybee (Apis mellifera) venom. Melittin is a basic peptide consisting of 26 amino acids.[2]
Function
The principal function of melittin as a component of bee venom is to cause pain and destruction of tissue of intruders that threaten a beehive. However, in honey bees, melittin is not only expressed in the venom gland, but also in other tissues when infected with pathogens. The two venom molecules, melittin and secapin, that are over-expressed in honey bees infected with various pathogens, possibly indicate a role for melittin in the immune response of bees to infectious diseases.[3]
Structure
Melittin is a small peptide with no disulfide bridge; the N-terminal part of the molecule is predominantly hydrophobic and the C-terminal part is hydrophilic and strongly basic. In water, it forms a tetramer but it also can spontaneously integrate itself into cell membranes.[4]
Mechanism of action
Injection of melittin into animals and humans causes pain sensation. It has strong surface effects on cell membranes causing pore-formation in epithelial cells and the destruction of red blood cells. Melittin also activates nociceptor (pain receptor) cells through a variety of mechanisms.[2]
Melittin can open thermal nociceptor TRPV1 channels via cyclooxygenase metabolites resulting in depolarization of nociceptor cells. The pore forming effects in cells causes the release of pro-inflammatory cytokines. It also activates G-protein-coupled receptor-mediated opening of transient receptor potential channels. Finally melittin up-regulates the expression of Nav1.8 and Nav1.9 sodium channels in nociceptor cell causing long term action potential firing and pain sensation.[2]
Melittin inhibits protein kinase C, Ca2+/calmodulin-dependent protein kinase II, myosin light chain kinase, and Na+/K+-ATPase (synaptosomal membrane). Melittin blocks transport pumps such as the Na+-K+-ATPase and the H+-K+-ATPase.[2]
Toxicity of a bee sting
Melittin is the main compound in bee venom, accounting for the potential lethality of a bee sting, which causes an anaphylactic reaction in some people.[5] At the sites of multiple stings, localized pain, swelling, and skin redness occur, and if bees are swallowed, life-threatening swelling of the throat and respiratory passages may develop.[5]
Use
Bee venom therapy has been used in traditional medicine for treating various disorders,[6] although its non-specific toxicity has limited scientific research on its potential effects.[7]
References
- ↑ Melitten - Compound Summary, PubChem.
- ↑ 2.0 2.1 2.2 2.3 "Melittin, the Major Pain-Producing Substance of Bee Venom". Neuroscience Bulletin 32 (3): 265–272. 2016. doi:10.1007/s12264-016-0024-y. PMID 26983715.
- ↑ "Unity in defence: honeybee workers exhibit conserved molecular responses to diverse pathogens". BMC Genomics 18 (1): 207. March 2017. doi:10.1186/s12864-017-3597-6. PMID 28249569.
- ↑ "The structure of melittin. II. Interpretation of the structure". The Journal of Biological Chemistry 257 (11): 6016–6022. 1982. doi:10.1016/S0021-9258(20)65098-0. PMID 7076662. http://www.jbc.org/content/257/11/6016.full.pdf.
- ↑ 5.0 5.1 "Bee venom". Drugs.com. 8 June 2020. https://www.drugs.com/npp/bee-venom.html.
- ↑ "Melittin, a major peptide component of bee venom, and its conjugates in cancer therapy". Cancer Letters 402: 16–31. 2017. doi:10.1016/j.canlet.2017.05.010. PMID 28536009.
- ↑ "Application of bee venom and its main constituent melittin for cancer treatment". Cancer Chemotherapy and Pharmacology 78 (6): 1113–1130. 2016. doi:10.1007/s00280-016-3160-1. PMID 27677623.
External links
- Melitten at the US National Library of Medicine Medical Subject Headings (MeSH)
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