Peptides are among the most widely studied molecules in modern life-science research. This primer covers what they are, how they are made, and the terminology you will encounter across a research catalogue.
What is a peptide?
A peptide is a short chain of amino acids joined by peptide bonds — covalent links formed when the carboxyl group of one amino acid reacts with the amino group of the next, releasing a molecule of water. Chains of roughly 2–50 amino acids are generally described as peptides; longer chains fold into proteins. The order of amino acids is the peptide’s sequence, and it determines the molecule’s properties and the receptors or pathways it is studied against.
How peptides are formed
In nature, peptides are produced ribosomally (translated from messenger RNA) or non-ribosomally (assembled by dedicated enzymes). For research, peptides are manufactured synthetically. Solid-phase peptide synthesis (SPPS) is the modern standard: the chain is built one protected amino acid at a time on a solid resin, then cleaved and purified. Purity and identity are confirmed analytically before a batch is released.
Common classes of research peptides
- Signaling peptides — studied for their interactions with specific cell-surface receptors.
- Structural / matrix peptides — investigated in tissue, cytoskeletal and extracellular-matrix research.
- Metabolic peptides — incretin and related analogues used in metabolic-pathway studies.
- Fragments and analogues — modified sequences used as reference standards or mechanistic tools.
Key terms
- Amino acid — the building block of a peptide.
- Sequence — the ordered list of amino acids.
- Lyophilised — freeze-dried to a stable powder for storage and shipping.
- Reconstitution — dissolving the powder in a suitable diluent for laboratory use.
- COA — Certificate of Analysis; the lab report confirming identity and purity for a specific lot.