Substance P (5-11), also known as Hepta Substance P, is the C-terminal heptapeptide Gln-Gln-Phe-Phe-Gly-Leu-Met-NH₂. It preserves the native amidated C-terminus and the hydrophobic Phe-Phe-Gly-Leu-Met sequence of Substance P.

The fragment provides an intermediate truncation between the shorter SP(6-11) pharmacophore and longer NK1-active Substance P fragments. It is useful for investigating how progressive N-terminal extension changes receptor interaction, peptide conformation, proteolytic processing and biological activity.

Product Information

Adding Gln5 Extends the C-Terminal Pharmacophore

Compared with SP(6-11), this fragment contains one additional N-terminal glutamine. Progressive extension toward the native Substance P sequence can alter receptor affinity, conformational preference and susceptibility to peptide-processing enzymes.

The difference is useful in truncation series because it allows the contribution of a single additional residue to be evaluated without changing the conserved C-terminal sequence.

Research Applications

Substance P (5-11) can support tachykinin structure–activity studies, peptide metabolism research, C-terminal fragment comparisons and receptor pharmacology.

Because Met11 remains present, methionine oxidation should be considered in stability-sensitive experiments.

Frequently Asked Questions

What is the sequence of SP(5-11)?

Gln-Gln-Phe-Phe-Gly-Leu-Met-NH₂.

How does it differ from SP(6-11)?

SP(5-11) contains one additional N-terminal Gln residue.

Is the peptide amidated?

Yes. Native Met11-NH₂ is retained.

Research Use Only.