VV-hemorphin-7

Also known as VV-H7; VVYPWTQRF

A nine-residue haemorphin retaining an N-terminal Val-Val extension, used in comparative receptor and proteolysis research.

Length: 9 amino acids
Half-life: Not well characterised
Mechanism: VV-hemorphin-7 interacts with opioid receptor systems and has been investigated for binding at the AT4 site associated with insulin-regulated aminopeptidase (IRAP). Its N-terminal extension can influence target recognition and proteolytic processing, so findings for LVV-hemorphin-7 should not be assumed to apply unchanged.
Studied in: Opioid receptor assays, AT4-site binding preparations and haemoglobin digestion models study its target interactions and relationship to neighbouring haemorphin fragments.

About VV-hemorphin-7

VV-hemorphin-7 is the nonapeptide Val-Val-Tyr-Pro-Trp-Thr-Gln-Arg-Phe, written VVYPWTQRF. It comprises the seven-residue haemorphin core with two additional N-terminal valines from the haemoglobin beta-chain sequence. Characterisation of haemoglobin-derived peptides established that related fragments can differ by only one or a few terminal residues. VV-hemorphin-7 illustrates this relationship: it lacks the initial leucine of LVV-hemorphin-7 but retains the same remaining sequence, including the internal Tyr-Pro-Trp-Thr motif and C-terminal Gln-Arg-Phe segment.

Comparative studies use VV-hemorphin-7 to examine how an N-terminal valine pair affects opioid-system interactions and AT4-associated binding. Differences from LVV-hemorphin-7 can reflect altered target recognition, stability or processing rather than peptide length alone. Because IRAP constitutes the AT4-associated binding protein, binding experiments and aminopeptidase activity assays answer related but different questions. Biological extracts may contain several haemorphins simultaneously, so analytical separation is important before assigning a measured response to this specific sequence.

Laboratory notes

Confirm the nine-residue sequence by mass spectrometry and check for LVV-hemorphin-7 or hemorphin-7 impurities.
Use separate binding and catalytic assays when characterising AT4/IRAP interactions; displacement alone does not quantify enzyme inhibition.
Monitor sequence stability in biological matrices and avoid repeated freeze–thaw cycles by preparing validated single-use aliquots.

Storage and reconstitution basics: storage guide.

Questions about VV-hemorphin-7

What distinguishes VV-hemorphin-7 from LVV-hemorphin-7?

VV-hemorphin-7 lacks the N-terminal leucine. Its sequence is VVYPWTQRF rather than LVVYPWTQRF.

Can VV-hemorphin-7 arise from processing of LVV-hemorphin-7?

Removal of the N-terminal leucine can generate this sequence. Whether it occurs in a particular preparation depends on the enzymes present and their substrate specificity.

Should receptor selectivity be inferred from the haemorphin name?

No. The name identifies a sequence family, not a fixed receptor-selectivity profile. Binding and functional activity require characterisation in the specific assay system.

Is VV-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

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