Compound Type
Peptide
Last updated
A chain of amino acids, conventionally between two and about fifty, that acts as a signalling molecule rather than as a structural or enzymatic protein. This site fixes the upper bound at 50 amino acids so that every compound lands in exactly one type. That boundary is a convention rather than a fact of chemistry: different sources put it at 40, 50 or 100, and nothing about a molecule changes when it crosses the line.
Why it matters here
Type decides how a record behaves across the site. Peptides are the compounds that arrive as a freeze-dried powder, need reconstituting with a vehicle, and carry a beyond-use date once they are in solution.
What it is not
Peptide in commerce is a marketing word that covers things which are not peptides at all, including small molecules, polynucleotides, vitamin cofactors and exosome preparations. The 50-amino-acid line is genuinely arbitrary as well: insulin at 51 residues is called a protein and is still widely called a peptide hormone, and that disagreement is real rather than an error.
Also called
- peptide
- research peptide
- bioactive peptide
Research peptide is a label about how a vial is sold and marked, not a statement about the molecule inside it.
Where it sits
- Narrower terms
- Cosmetic Peptide
Compounds carrying this term
None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.