Identity
- Class
- Venom
- Molecular weight
- 2027 Da
- Residues
- 18
- Heavy atoms
- 138
- Reference slug
- apamin
These are published properties of the molecule, given for identification. Values we cannot confirm are omitted rather than estimated. What these terms mean.
What this compound is
Eighteen residues with two disulfides pulling the ends toward the middle, so a short helix at the back is clamped against the front of the chain.
Sequence
| 1 | CNCKAPETAL CARRCQQH |
|---|
- Three-letter code
- Cys-Asn-Cys-Lys-Ala-Pro-Glu-Thr-Ala-Leu-Cys-Ala-Arg-Arg-Cys-Gln-Gln-His
The one-letter code gives the amino-acid backbone. Terminal modifications, where a compound carries them, are accounted for in the molecular weight above but are not visible in the letters.
Residue composition
Counted directly from the sequence above. Apamin is built from 11 of the twenty standard amino acids across 18 positions.
By residue
| Residue | Code | Count | Share |
|---|---|---|---|
| Cysteine | C · Cys | 4 | 22.2% |
| Alanine | A · Ala | 3 | 16.7% |
| Glutamine | Q · Gln | 2 | 11.1% |
| Arginine | R · Arg | 2 | 11.1% |
| Glutamic acid | E · Glu | 1 | 5.6% |
| Histidine | H · His | 1 | 5.6% |
| Lysine | K · Lys | 1 | 5.6% |
| Leucine | L · Leu | 1 | 5.6% |
| Asparagine | N · Asn | 1 | 5.6% |
| Proline | P · Pro | 1 | 5.6% |
| Threonine | T · Thr | 1 | 5.6% |
By side-chain class
Nonpolar, aliphatic
5 · 27.8%
A L P
Polar, uncharged
8 · 44.4%
C N Q T
Positively charged
4 · 22.2%
H K R
Negatively charged
1 · 5.6%
E
Side-chain classes follow the standard grouping of the twenty proteinogenic amino acids. Composition is arithmetic over the published sequence and says nothing about how the molecule behaves.
Others in Venom
Alpha-conotoxin ImI
12 residues · 1352 Da
Twelve residues, the smallest conotoxin here, with the same nested bond pattern as conotoxin GI.…
Reference entry
Chlorotoxin
36 residues · 3997 Da
Thirty-six residues with four disulfides, tying it for the most bonded structure here alongside…
Reference entry
Conotoxin GI
13 residues · 1438 Da
Thirteen residues closed by two disulfides that nest inside one another rather than crossing. Co…
Reference entry
Mast cell degranulating peptide
22 residues · 2587 Da
Twenty-two residues sharing apamin's two-disulfide plan and its cysteine spacing. Both come from…
Reference entry
Sarafotoxin S6b
21 residues · 2515 Da
Twenty-one residues with two nested disulfides. Almost identical in shape to the endothelins, wh…
Reference entry
Ziconotide
25 residues · 2639 Da
Twenty-five residues from cone snail venom, folded by three disulfides. Two of its cysteines sit…
Reference entry
This is a reference entry. Sequence, residue count, molecular weight and atom count are published properties of the molecule, given for identification. Nothing on this page describes an application, benefit, dose, route or outcome, and nothing here should be read as an offer to supply or as guidance for use in a person or an animal. Materials sold by PepXtide are for laboratory research use only, are not for human or animal consumption, and have not been evaluated by the FDA.