Identity
- Class
- Antimicrobial
- Molecular weight
- 3835 Da
- Residues
- 35
- Heavy atoms
- 270
- Reference slug
- cecropin-b
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
Thirty-five residues in two helices joined by a hinge: a charged one at the front and a hydrophobic one at the back. One of the first antimicrobial peptides ever described.
Sequence
| 1 | KWKVFKKIEK MGRNIRNGIV KAGPAIAVLG EAKAL |
|---|
- Three-letter code
- Lys-Trp-Lys-Val-Phe-Lys-Lys-Ile-Glu-Lys-Met-Gly-Arg-Asn-Ile-Arg-Asn-Gly-Ile-Val-Lys-Ala-Gly-Pro-Ala-Ile-Ala-Val-Leu-Gly-Glu-Ala-Lys-Ala-Leu
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. Cecropin B is built from 13 of the twenty standard amino acids across 35 positions.
By residue
| Residue | Code | Count | Share |
|---|---|---|---|
| Lysine | K · Lys | 7 | 20% |
| Alanine | A · Ala | 5 | 14.3% |
| Glycine | G · Gly | 4 | 11.4% |
| Isoleucine | I · Ile | 4 | 11.4% |
| Valine | V · Val | 3 | 8.6% |
| Glutamic acid | E · Glu | 2 | 5.7% |
| Leucine | L · Leu | 2 | 5.7% |
| Asparagine | N · Asn | 2 | 5.7% |
| Arginine | R · Arg | 2 | 5.7% |
| Phenylalanine | F · Phe | 1 | 2.9% |
| Methionine | M · Met | 1 | 2.9% |
| Proline | P · Pro | 1 | 2.9% |
| Tryptophan | W · Trp | 1 | 2.9% |
By side-chain class
Nonpolar, aliphatic
20 · 57.1%
A G I L M P V
Aromatic
2 · 5.7%
F W
Polar, uncharged
2 · 5.7%
N
Positively charged
9 · 25.7%
K R
Negatively charged
2 · 5.7%
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 Antimicrobial
Alloferon
13 residues · 1265 Da
Thirteen residues, six of them glycine and four histidine, which makes the backbone unusually fl…
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Aurein 1.2
13 residues · 1480 Da
Thirteen residues forming a short helix with a clear split between its charged and greasy faces.
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Beta-defensin 2
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Forty-one residues with three disulfides in a different arrangement to the alpha-defensin above.…
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Buforin II
21 residues · 2435 Da
Twenty-one residues cut from histone H2A, the protein that packages DNA. A proline in the middle…
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Citropin 1.1
16 residues · 1615 Da
Sixteen residues opening with the same glycine-leucine-phenylalanine-aspartate as aurein, which…
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.