Substance P-Gly-Lys-Arg is a 14-residue peptide corresponding to β-preprotachykinin (58-71). It contains the complete Substance P sequence followed by a Gly-Lys-Arg extension.

The C-terminal GKR sequence makes this peptide particularly relevant to neuropeptide precursor processing rather than simply functioning as an extended Substance P analog.

Product Information

The GKR Extension Is a Peptide-Processing Signal

Mature Substance P terminates in Met-NH₂, whereas this precursor peptide continues with Gly-Lys-Arg.

In neuropeptide biosynthesis, dibasic Lys-Arg motifs provide proteolytic processing sites. The adjacent Gly can serve as the amide donor during enzymatic C-terminal amidation, allowing the precursor sequence to be converted into mature amidated Substance P.

This makes Substance P-Gly-Lys-Arg useful for studying precursor maturation, peptide-processing enzymes and the difference between biosynthetic intermediates and mature neuropeptides.

Why It Should Not Be Treated as Ordinary Substance P

The precursor has three additional residues and a free C-terminal Arg rather than the Met-NH₂ terminus of mature Substance P. Molecular weight, net charge and processing state are therefore different.

We recommend using mature Substance P as a separate control when the biological endpoint is intended to measure NK1 receptor activation.

Research Applications

The peptide can support preprotachykinin processing studies, neuropeptide amidation research, precursor–product comparisons and biochemical studies of peptide maturation.

Frequently Asked Questions

Is this mature Substance P?

No. It is an extended precursor segment containing Gly-Lys-Arg after the Substance P sequence.

What is the role of Gly-Lys-Arg?

The Lys-Arg pair provides a dibasic processing motif, while Gly can participate in biosynthetic formation of the C-terminal amide of mature Substance P.

Is the C-terminus amidated?

No. This 14-residue precursor sequence terminates in Arg-OH.

Research Use Only.