[D-Arg1,D-Pro2,D-Phe7,D-His9]-Substance P is an 11-residue stereochemically modified Substance P analog used as a neurokinin-1 receptor antagonist. Four positions contain D-amino acids, substantially changing the conformational behavior of the native tachykinin sequence.

The peptide is particularly useful for investigating how backbone stereochemistry can convert a receptor-active neuropeptide scaffold into an antagonist-oriented ligand.

Product Information

Stereochemical Remodeling of Substance P

D-Arg1 and D-Pro2 alter the N-terminal conformational preferences, while D-Phe7 and D-His9 modify the receptor-facing C-terminal half of the peptide.

NMR studies in membrane-mimetic environments found that this analog adopts a defined C-terminal turn distinct from agonist tachykinins, providing a structural framework for understanding antagonist recognition.

NK1 Receptor Antagonism

Substance P analogs containing D-His9 were historically developed as tachykinin antagonists. Experimental studies showed selective inhibition of Substance P-related behavioral responses consistent with blockade of spinal NK1 receptor signaling.

The molecule is therefore better positioned as a receptor antagonist and conformational SAR probe than as a generic “stable Substance P analog.”

Analytical Considerations

Because four residues have non-native stereochemistry, molecular identity cannot be established from nominal mass alone. Sequence specification and stereochemical control are important alongside HPLC purity and MS confirmation.

Our Peptide Quality Control capabilities support analytical characterization according to the selected specification.

Frequently Asked Questions

Is this peptide a Substance P agonist?

It is primarily used as an NK1 receptor antagonist.

Why are D-amino acids important?

They alter peptide conformation, proteolytic recognition and receptor interaction relative to the all-L native peptide.

Research Use Only.