Identity
- Class
- Hormonal
- Molecular weight
- 1665 Da
- Residues
- 13
- Heavy atoms
- 118
- Reference slug
- alpha-msh
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
Thirteen residues capped at both ends, an acetyl at one and an amide at the other, both drawn. The natural hormone that Melanotan I and II are analogues of, so it is worth comparing all three side by side.
Sequence
| 1 | SYSMEHFRWG KPV |
|---|
- Three-letter code
- Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val
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. Alpha-MSH is built from 12 of the twenty standard amino acids across 13 positions.
By residue
| Residue | Code | Count | Share |
|---|---|---|---|
| Serine | S · Ser | 2 | 15.4% |
| Glutamic acid | E · Glu | 1 | 7.7% |
| Phenylalanine | F · Phe | 1 | 7.7% |
| Glycine | G · Gly | 1 | 7.7% |
| Histidine | H · His | 1 | 7.7% |
| Lysine | K · Lys | 1 | 7.7% |
| Methionine | M · Met | 1 | 7.7% |
| Proline | P · Pro | 1 | 7.7% |
| Arginine | R · Arg | 1 | 7.7% |
| Valine | V · Val | 1 | 7.7% |
| Tryptophan | W · Trp | 1 | 7.7% |
| Tyrosine | Y · Tyr | 1 | 7.7% |
By side-chain class
Nonpolar, aliphatic
4 · 30.8%
G M P V
Aromatic
3 · 23.1%
F W Y
Polar, uncharged
2 · 15.4%
S
Positively charged
3 · 23.1%
H K R
Negatively charged
1 · 7.7%
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 Hormonal
Kisspeptin-10
10 residues · 1302 Da
Ten residues, the shortest fragment that retains activity at its receptor. The C-terminal amide…
In our catalogue
Melanotan I
13 residues · 1647 Da
Alpha-MSH with two substitutions: the methionine at four becomes norleucine, which cannot oxidis…
In our catalogue
Melanotan II
7 residues · 1024 Da
Seven residues closed into a ring by a side-chain lactam: the aspartate at two and the lysine at…
In our catalogue
PT-141
7 residues · 1025 Da
The same ring as Melanotan II, differing only at the C-terminus, which is a free acid here rathe…
In our catalogue
ACTH 1-13
13 residues · 1624 Da
The same thirteen residues as alpha-MSH but without the caps at either end. Putting the two next…
Reference entry
ACTH 1-24
24 residues · 2933 Da
Twenty-four residues, the shortest fragment of corticotropin that keeps full activity at the rec…
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.