Spinorphin

Also known as LVVYPWT

A seven-residue haemoglobin-related peptide studied as an inhibitor of enzymes that degrade enkephalins.

Length: 7 amino acids
Half-life: Not well characterised
Mechanism: Spinorphin inhibits several peptidases involved in enkephalin degradation, including aminopeptidase N, neprilysin and dipeptidyl peptidase III in biochemical assays. Its activity is primarily characterised through enzyme inhibition rather than a single established receptor target.
Studied in: Purified-enzyme assays, neural tissue preparations and animal nociceptive-signalling models examine its effects on peptide degradation and endogenous opioid signalling.

About Spinorphin

Spinorphin is the heptapeptide Leu-Val-Val-Tyr-Pro-Trp-Thr, written LVVYPWT. Originally isolated from bovine spinal cord, its sequence corresponds to a segment of the haemoglobin beta chain and overlaps the haemorphin family. Unlike the conventionally named haemorphins, which contain an exposed Tyr-Pro-Trp sequence at their N-terminus or within longer extensions, spinorphin is particularly associated with inhibition of enkephalin-degrading enzymes. Its isolation helped connect endogenous peptide fragments with regulation of extracellular neuropeptide breakdown.

Biochemical investigations have examined aminopeptidase N, neprilysin and dipeptidyl peptidase III as spinorphin-sensitive enzymes. Inhibiting these enzymes can change how quickly enkephalins disappear from an experimental preparation, so an apparent opioid-system effect need not imply direct opioid receptor agonism. Researchers use defined substrates, tissue extracts and antagonist-controlled animal models to separate these mechanisms. Potency depends on the enzyme source, substrate and assay conditions; values from different experimental systems are not interchangeable.

Laboratory notes

Confirm sequence and terminal chemistry by mass spectrometry; spinorphin and related haemorphins have overlapping sequences but distinct activities.
Use substrate-only, enzyme-only and peptide-only controls in fluorescence assays to identify background signals or optical interference.
Prepare single-use aliquots under validated storage conditions and monitor tryptophan oxidation or peptide degradation by chromatography.

Storage and reconstitution basics: storage guide.

Questions about Spinorphin

How does spinorphin differ from LVV-hemorphin-7?

Spinorphin is LVVYPWT, whereas LVV-hemorphin-7 is LVVYPWTQRF. The additional C-terminal residues distinguish their structures and can alter enzyme and receptor interactions.

Does an opioid-related assay response establish direct receptor binding?

No. Reduced enkephalin degradation can indirectly influence opioid signalling. Direct binding and receptor-functional assays are needed to establish receptor interactions.

Which assay best tests its peptidase-inhibitory activity?

A defined enzyme–substrate assay with an orthogonal chromatographic measurement of substrate cleavage helps distinguish genuine inhibition from detection interference.

Is Spinorphin 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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