Immune & Antimicrobial

Melittin

Melittin is what a bee sting feels like — the main peptide of honeybee venom, and the reason the pain arrives instantly. It destroys cell membranes on contact, which in a test tube makes it a formidable killer of the organisms that defeat antibiotics: extensively drug-resistant Acinetobacter, methicillin-resistant Staphylococcus aureus (MRSA) and carbapenemase-producing Klebsiella all fall at 8 to 32 micrograms per millilitre. Half of human red blood cells burst at 0.44. Those two numbers are the whole field in miniature: in infected mice, repeated dosing at the highest survivable level changed neither survival nor bacterial load while colistin and vancomycin did, because the concentration that kills the bacteria cannot be reached inside a living body.

Last updated 12 August 2026

Studied forAntimicrobial research · Cytotoxicity and oncology research · Membrane pore-forming context

Evidence on file2 animal studies · 1 computational study · 2 citations not yet graded

Strongest sourceMelittin attenuates imiquimod-induced psoriatic dermatitis in mice: a role for autophagy activation via PI3K/… (animal study)

Mechanism

Amphipathic cationic helix that binds and permeabilises lipid bilayers, forming pores and potentiating phospholipase A2 activity.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

Antimicrobial research
Cytotoxicity and oncology research
Membrane pore-forming context

Dosing on file unverified

Topical Phase I (IRCT20190924044863N1); No established systemic dose

Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.

Literature on file 6

review or editorial
Multidimensional Modification and Functional Optimization of Melittin: From Natural Toxic Peptide to Safe and Effective Therapeutics. graded on: indexed as "Review" - secondary literature, not a study — “Review”
computational
Optimizing separation conditions for melittin purification from bee venom using molecular dynamics simulations. graded on: a computational prediction — “molecular dynamics”
animal in vivo
Melittin attenuates imiquimod-induced psoriatic dermatitis in mice: a role for autophagy activation via PI3K/Akt/mTOR pathway suppression. graded on: an animal model — “mice”
animal in vivo
Antimicrobial peptides from arthropod venoms exhibit activity against Sporothrix species. graded on: an animal model — read from the indexed abstract — “murine”

Not graded

2 citations whose study design could not be read from the title. Left ungraded rather than guessed at.

Identity

Space-filling 3D model of Melittin, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Melittin — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 2846.5
Molecular formula: C131H229N39O31
CAS number: 37231-28-0
PubChem CID: 16133648
UniProt: P01504
InChI key: VDXZNPDIRNWWCW-JFTDCZMZSA-N
SMILES: CC[C@H](C)[C@@H](C(=O)NCC(=O)N[C@@H](C)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H]([C@@H](C)O)C(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N1CCC[C@H]1C(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CO)C(=O)N[C@@H](CC2=CNC3=CC=CC=C32)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCC(=O)N)C(=O)N)NC(=O)CN
InChI: InChI=1S/C131H229N39O31/c1-23-71(16)102(163-97(176)60-135)122(194)146-62-98(177)148-74(19)109(181)164-100(69(12)13)124(196)160-88(55-65(4)5)116(188)155-84(41-30-33-51-134)115(187)165-101(70(14)15)125(197)161-90(57-67(8)9)118(190)168-106(77(22)173)128(200)169-105(76(21)172)123(195)147-63-99(178)150-92(58-68(10)11)129(201)170-54-36-44-94(170)121(193)149-75(20)108(180)158-89(56-66(6)7)117(189)166-104(73(18)25-3)127(199)162-93(64-171)120(192)159-91(59-78-61-145-80-38-27-26-37-79(78)80)119(191)167-103(72(17)24-2)126(198)157-83(40-29-32-50-133)111(183)154-85(42-34-52-143-130(139)140)112(184)152-82(39-28-31-49-132)110(182)153-86(43-35-53-144-131(141)142)113(185)156-87(46-48-96(137)175)114(186)151-81(107(138)179)45-47-95(136)174/h26-27,37-38,61,65-77,81-94,100-106,145,171-173H,23-25,28-36,39-60,62-64,132-135H2,1-22H3,(H2,136,174)(H2,137,175)(H2,138,179)(H,146,194)(H,147,195)(H,148,177)(H,149,193)(H,150,178)(H,151,186)(H,152,184)(H,153,182)(H,154,183)(H,155,188)(H,156,185)(H,157,198)(H,158,180)(H,159,192)(H,160,196)(H,161,197)(H,162,199)(H,163,176)(H,164,181)(H,165,187)(H,166,189)(H,167,191)(H,168,190)(H,169,200)(H4,139,140,143)(H4,141,142,144)/t71-,72-,73-,74-,75-,76+,77+,81-,82-,83-,84-,85-,86-,87-,88-,89-,90-,91-,92-,93-,94-,100-,101-,102-,103-,104-,105-,106-/m0/s1

Notes unverified prose

Phase I topical (soft tissue infections); no systemic human trials; severe hemolysis limits clinical translation; preclinical only; Phase I topical (IRCT20190924044863N1); systemic hemolysis limits use

Not on file 2

1 of the 8 fields we track hold nothing on this record, and each says why. 1 further absence is named below. A blank field is a bug; a named absence is a finding.

amino-acid sequencenothing we hold supplies it
half-lifenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.