GPR56 P7 peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

GPR56 is an adhesion G protein-coupled receptor (aGPCR) that can be activated by its endogenous ligand, collagen III, and by a synthetic seven-amino-acid peptide (TYFAVLM), designated P7. This peptide is derived from the Stachel sequence located within the N-terminal region of GPR56. P7 functions as a partial agonist, inducing rapid increases in intracellular calcium in a GPR56-dependent manner. Studies using SNAP-tag labeling and super-resolution microscopy reveal that GPR56 undergoes constitutive internalization and recycling in the absence of exogenous agonists, a process distinct from many typical GPCRs. While collagen III further stimulates GPR56 internalization, P7 does not significantly promote additional receptor trafficking beyond this basal level.

The activation of GPR56 by P7 is linked to downstream signaling events, including calcium mobilization. In pancreatic beta-cells, P7 induces a rapid and reversible increase in intracellular calcium and can potentiate glucose-stimulated insulin secretion. These functional responses occur without significant effects on receptor internalization, suggesting that P7 may act as a biased agonist at GPR56, engaging specific signaling pathways without driving receptor endocytosis.

• Stoveken HM, Hajduczok AG, Xu L, Tall GG. Adhesion G protein-coupled receptors are activated by exposure of a cryptic tethered agonist. Proc Natl Acad Sci U S A. 2015 May 12;112(19):6194-9. doi: 10.1073/pnas.1421785112. Epub 2015 Apr 27. Erratum in: Proc Natl Acad Sci U S A. 2015 Jun 30;112(26):E3452. PMID: 25918380; PMCID: PMC4434738.
• Olaniru OE, Cheng J, Ast J, Arvaniti A, Atanes P, Huang GC, King AJF, Jones PM, Broichhagen J, Hodson DJ, Persaud SJ. SNAP-tag-enabled super-resolution imaging reveals constitutive and agonist-dependent trafficking of GPR56 in pancreatic β-cells. Mol Metab. 2021 Nov;53:101285. doi: 10.1016/j.molmet.2021.101285. Epub 2021 Jul 2. PMID: 34224919; PMCID: PMC8326393.

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.