Substance P (9-11) is the C-terminal tripeptide Gly-Leu-Met-NH₂ derived from the native Substance P sequence.

The peptide is useful primarily as a compact C-terminal fragment and peptide-processing product rather than as a substitute for full-length Substance P in NK1 receptor activation studies.

Product Information

A Natural C-Terminal Substance P Degradation Fragment

Enzymatic degradation studies of Substance P have identified SP(9-11) among the C-terminal products generated by Substance P-degrading endopeptidase activities.

This makes GLM-NH₂ useful in peptide metabolism and degradation experiments where fragment identity is more important than receptor agonist potency.

The Tripeptide Is Too Short to Reproduce Full NK1 Pharmacology

In NK1 receptor binding studies, Substance P (9-11) failed to compete effectively for high-affinity Substance P binding sites in a mast-cell model.

We therefore recommend this peptide as a fragment/metabolite standard rather than as a positive NK1 agonist control.

Free Peptide Versus Hydrochloride Salt

CAS 4652-64-6 corresponds to Gly-Leu-Met-NH₂. Some commercial listings use CAS 40297-96-9 for the hydrochloride salt. Salt form should be checked before comparing molecular weight or preparing molar solutions.

Research Applications

Substance P (9-11) can support peptide degradation studies, Substance P metabolite identification, LC-MS method development and C-terminal fragment SAR.

Frequently Asked Questions

What is the sequence?

Gly-Leu-Met-NH₂.

Is SP(9-11) a good NK1 agonist control?

No. It lacks most of the Substance P sequence and has shown weak or absent competition at high-affinity NK1-associated binding sites.

Why do some suppliers show a different CAS?

CAS 40297-96-9 is used for an HCl salt, whereas 4652-64-6 corresponds to the non-HCl peptide form.

Research Use Only.