01 / Molecular architecture
A closer look at the chain.
The seven-residue reference contains an Asp2–Lys7 lactam ring and an N-terminal acetyl group. Its C-terminal acid distinguishes it from the amidated Melanotan-2 reference.
- 7 residues
- Asp2–Lys7 lactam ring
- C-terminal acid
- 1Nle
- 2Asp
- 3His
- 4D-Phe
- 5Arg
- 6Trp
- 7Lys
Reference information: [1][2]. Actual lot identity must be verified separately.
Three structural details to read together.
The PT-141 reference combines an N-terminal acetyl group, an Asp2–Lys7 side-chain lactam and a C-terminal acid. The residue list is only one layer of this description. Including the ring and both end groups makes the comparison with related melanocortin peptides more precise.
A shared ring, a different terminal group.
The closely related Melanotan-2 reference uses an amidated C-terminus. PT-141’s acid ending means the two references should not be collapsed into a single identity merely because their sequence diagrams contain the same residue names. Terminal chemistry is part of the molecule, not a formatting detail.
Structure and research references: [1]
02 / Read the evidence
Research & analytical context.
The reference literature places PT-141 in melanocortin-receptor research, including MC4R activity. A receptor designation describes an experimental pathway, not the quality of a particular vial.
The distinction that matters
PT-141 and Melanotan-2 share residue names but differ at the C-terminus. A sequence schematic alone cannot establish their equivalence; terminal chemistry must be included in the identity record.
03 / From reference to record
Know the lot, too.
A publication describes its own test material. Your lot’s certificate describes what was tested on that lot. Keep the compound name, batch number and reported methods together when reviewing a result.
Identity & composition
Check sequence or chemical form, terminal modifications, counterion and—where relevant—each blend component.
Analytical results
Read purity, content, sterility and endotoxin results as separate measurements. Only call a test passed when the actual report supports it.
Handling & storage notes
Lyophilized material: Store at −20°C; protect from light and moisture.
Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.
How to store lyophilized peptides04 / Reference questions
A few details, explained.
Is bremelanotide another name for PT-141?
Yes, it is used for the PT-141 reference identity. Matching synonyms is useful, but the complete chemical specification remains the basis for comparing materials.
Does the ring join the first and last residues directly?
The described lactam links the side chains of Asp2 and Lys7. That is a specific connection and should not be replaced with an unspecified head-to-tail ring in a structure illustration.
Read alongside the references: [1]
05 / Continue reading
Go to the source.
Each source is labeled by its type. External sources are not Pioneer batch certificates.