Amino-Acid Sequence
Also known as: peptide sequence · primary structure · sequence
The specific order of amino-acid residues in a peptide — its "primary structure" — which dictates shape and activity.
The sequence (or primary structure) is the exact order in which amino-acid residues are linked in a peptide, conventionally written from the N-terminus to the C-terminus using three-letter or one-letter codes.
Sequence is destiny: it determines how the chain folds, what it binds to and how it behaves — a single substituted residue can change activity or stability. It is also what mass spectrometry checks a batch against.
Small, defined sequences are what make research peptides reproducible — the same sequence, verified batch to batch, should behave the same way.
RELATED TERMS
Amino Acid
The building-block molecules of peptides and proteins; each contributes one residue to the chain.
Peptide Bond
The covalent amide bond linking amino acids into a peptide chain — the defining structural feature of every peptide.
N-terminus & C-terminus
The two ends of a peptide chain: the N-terminus has a free amino group, the C-terminus a free carboxyl group.
Analog
A peptide deliberately modified from a natural sequence to improve stability, selectivity or potency.
Mass Spectrometry
An analytical method that measures a molecule’s mass to confirm a peptide’s identity matches its intended sequence.
Educational content, not medical advice. All products supplied for research purposes only — not for human consumption.