Other · Haemoglobin-derived opioid peptide
Hemorphin-7
Also known as H7; YPWTQRF
A seven-residue haemorphin with an exposed N-terminal tyrosine, studied in opioid receptor and peptide-processing assays.
- Length
- 7 amino acids
- Half-life
- Not well characterised
- Mechanism
- Hemorphin-7 interacts with opioid receptors through its haemorphin sequence, with activity influenced by receptor subtype and experimental system. Its N-terminal Tyr-Pro-Trp-Thr motif and C-terminal Gln-Arg-Phe extension provide a framework for studying structure–activity relationships.
- Studied in
- Receptor-binding assays, cell-based opioid signalling systems and enzymatic haemoglobin digests examine its molecular recognition and proteolytic generation.
About Hemorphin-7
Hemorphin-7 is the linear heptapeptide Tyr-Pro-Trp-Thr-Gln-Arg-Phe, or YPWTQRF. Its sequence lies within the haemoglobin beta chain and includes the YPWT motif found in hemorphin-4. Research into opioid-active haemoglobin digestion products established the broader haemorphin family, with longer fragments subsequently characterised as distinct molecular species. Hemorphin-7 serves as the unextended sequence underlying VV-hemorphin-7 and LVV-hemorphin-7, both of which retain additional residues at the N-terminus from the parent protein.
An exposed N-terminal tyrosine distinguishes hemorphin-7 from its valine-extended relatives and is relevant to opioid receptor recognition. The C-terminal glutamine, arginine and phenylalanine also change its charge distribution and interaction surface compared with hemorphin-4. Experimental comparisons therefore address both terminal accessibility and peptide length. In complex preparations, aminopeptidases and other proteases may generate shorter products; measuring intact peptide alongside receptor responses helps distinguish starting-material activity from effects associated with processing.
Laboratory notes
- Resolve hemorphin-7 from N-terminally extended variants and truncated impurities using an appropriate chromatographic method.
- Control buffer pH and ionic strength across comparisons because these variables influence peptide charge and receptor-assay behaviour.
- Pair functional receptor measurements with peptide-stability checks when using cell preparations that may contain extracellular peptidases.
Storage and reconstitution basics: storage guide.
Questions about Hemorphin-7
What is the sequence of hemorphin-7?
The sequence is YPWTQRF: Tyr-Pro-Trp-Thr-Gln-Arg-Phe.
Why compare hemorphin-7 with its VV and LVV variants?
These comparisons isolate the influence of N-terminal extensions on molecular recognition, enzymatic processing and assay-dependent activity.
Does opioid receptor binding establish functional activation?
No. Binding establishes interaction under the assay conditions; functional measurements, such as receptor-dependent second-messenger assays, are needed to characterise activation.
Is Hemorphin-7 for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.