A sequence tells the supplier which amino acids to assemble. For a cyclic peptide, it may not tell them which positions should connect. Include both the sequence and the connection map so that “cyclic” has a precise meaning in your order.
There is more than one way to make a ring
JPT’s cyclic-peptide guidance describes different designs, including head-to-tail closure, side-chain links and disulfide bridges. These involve different connection points or chemistry. If a paper shows a structure, send that structure rather than translating every example into the single phrase “make it cyclic.”
Four cysteines can be paired three ways
Consider an invented sequence with cysteines at positions 1, 4, 8 and 11. If all four form two disulfide bridges, the possible pairings are (1–4, 8–11), (1–8, 4–11) and (1–11, 4–8). This is a counting example. It does not claim that all three structures can be made, fold correctly or have the same activity.
A matching mass does not draw the connection map
The three pairings above contain the same residues and the same number of bridges. Their expected mass alone therefore does not distinguish the pairings. Ask which evidence is needed to support the specified connectivity and whether it can be supplied. Do not treat a routine mass match as a full structural assignment.
Number the positions before requesting a quote
Send the sequence from N to C, number every residue and mark each connection pair. State whether any cysteines must remain unlinked, how the termini should be treated, and which structural documents your work requires. Ask the supplier to confirm the drawing before discussing price or delivery.
Useful links
For laboratory research, development and manufacturing only. Not for human or veterinary use.
Sources and examples
Reference records explain the topic; they do not establish NHD stock, a supplied lot’s results or clinical suitability. Examples explicitly labeled as hypothetical are calculations, not test data.
Sources & editorial method
AI-assisted drafting, source checks, translation and generated comic illustration. This is not independent peer review or supplied-lot verification.
1 linked records are listed in the references below. Read the editorial and AI-assistance policy.
How to interpret this article
Reference data and teaching examples are separated from NHD lot results; product specifications and availability require confirmation.
Research-use boundary: Catalog materials discussed on this website are for laboratory research, development and manufacturing use only, not for human or veterinary use. This content is not medical advice and does not provide administration instructions.
Primary records and authoritative sources
- JPT: cyclic peptidesProvider overview of distinct cyclization routes; the pairing example here is original arithmetic.
