Pinealon is a synthetic tripeptide with the sequence Glu-Asp-Arg (EDR). It belongs to the family of short regulatory peptides developed at the St Petersburg Institute of Bioregulation and Gerontology and is used in neuronal cell culture, oxidative stress assays and gene expression studies at the cellular level. NuVion supplies Pinealon as a laboratory chemical for in vitro research use only.
Key facts
| Type/class | Synthetic linear tripeptide, short regulatory peptide |
| Amino acid count | 3 |
| Sequence | H-Glu-Asp-Arg-OH (EDR) |
| Molecular formula | C15H26N6O8 |
| Molecular weight | 418.4 g/mol |
| Synonyms | EDR peptide, L-glutamyl-L-aspartyl-L-arginine, Glu-Asp-Arg |
| Supplied form | Lyophilised powder in a sealed vial |
Pinealon
$109 AUD
View productResearch use only. Not for human or veterinary use.
Structure and chemistry
Pinealon is not a cleavage product of a known protein. It was designed from the amino acid composition of polypeptide extracts of the pineal gland, in the same programme that produced the tetrapeptide Epithalon (Ala-Glu-Asp-Gly) and the dipeptide Thymogen (Glu-Trp). The three residues are all L-configured and unmodified, with a free N-terminal amine and a free C-terminal carboxylate.
The molecule is small and highly charged. At neutral pH it carries a positive charge on the N-terminal amine and on the arginine guanidinium, and negative charges on the glutamate side chain, the aspartate side chain and the C-terminal carboxylate, giving a net charge of about minus one. It has no aromatic residues, no sulfur and no hydrophobic side chains, so it is freely soluble in water, does not bind plastic to any meaningful degree, and has no absorbance above 220 nm. That last point matters for analysis: RP-HPLC detection has to be done at 210 to 220 nm, retention on C18 columns is weak unless an ion-pairing agent such as trifluoroacetic acid is used, and mass spectrometry (protonated molecule at m/z 419.2) is the more reliable identity check.
Two chemical liabilities are worth knowing. An N-terminal glutamate can slowly cyclise to pyroglutamate, which removes the terminal amine and shifts the mass by 18 Da, and the aspartyl peptide bond is the most acid-labile site in the chain. Both processes are slow in the lyophilised solid and in neutral, refrigerated solution, which is why the powder is kept dry and solutions are not stored for long periods.
Mechanism of action
Pinealon has no identified cell-surface receptor, and its mechanism is less settled than that of a hormone analogue. Two lines of in vitro evidence are used to frame experiments with it.
The first is a cellular redox and survival phenotype. In primary cerebellar granule cell cultures, neutrophils and the PC12 cell line, exposure to the tripeptide before an oxidative challenge (hydrogen peroxide, glutamate or a phorbol ester that activates NADPH oxidase) lowers the accumulation of reactive oxygen species measured by dichlorofluorescein fluorescence, reduces the fraction of propidium iodide-positive (necrotic) cells, and is accompanied by phosphorylation of ERK1/2 and a shift in cell cycle distribution. The ROS-limiting response saturates at low concentrations while the cell cycle response continues to change at higher concentrations, which was the original argument that more than one mechanism is involved.
The second is direct interaction with chromatin. Short, charged peptides of this class have been reported to pass through the plasma membrane and nuclear envelope of cultured cells, and fluorescently labelled peptides of this class accumulate in the nucleus and nucleolus. Molecular docking places EDR in the major groove of DNA, where the arginine guanidinium and the two carboxylates can form hydrogen bonds with base edges at particular sequences, and the working hypothesis is that peptide binding alters local chromatin accessibility and the transcription of nearby genes. In neuronal and neural progenitor cultures this has been followed as changes in transcript and protein levels of differentiation markers such as nestin, GAP43, beta-tubulin III and doublecortin. These models remain hypotheses at the level of gene regulation, and experiments are designed with that in mind.
Research applications
Pinealon is listed in NuVion’s Neuroscience category. Assay contexts in which it is used include:
- Reactive oxygen species assays (DCFH-DA, MitoSOX) in PC12 cells, SH-SY5Y cells and primary neuronal cultures under hydrogen peroxide or glutamate challenge
- Cell viability, necrosis and apoptosis readouts: propidium iodide and annexin V staining by flow cytometry, LDH release, caspase-3 activity
- Phospho-ERK1/2 western blotting and cell cycle analysis by DNA content, with time-course and concentration-response designs
- Gene expression profiling by qPCR and immunocytochemistry for neuronal differentiation markers in neural progenitor and neuronal cell lines
- Peptide-DNA interaction studies: molecular docking, electrophoretic mobility shift assays, circular dichroism and isothermal titration calorimetry with defined oligonucleotides
- Analytical method development for hydrophilic, chromophore-free peptides: ion-pair RP-HPLC, HILIC and LC-MS
Handling in the laboratory
The lyophilised powder dissolves immediately in bacteriostatic water; add the water to the vial and swirl gently. Use the reconstitution calculator to set the stock concentration from the vial content and the volume added. With a molecular weight of 418.4 g/mol, a 1 mg per mL stock is about 2.4 mM, so working dilutions into culture medium are usually large and the vehicle contribution is small. Keep the sealed vial dry, away from light and refrigerated as described in the product documentation. Keep reconstituted solution refrigerated and use it within the period stated in the documentation. Each lot is characterised by RP-HPLC for purity and by mass spectrometry for identity, and for a peptide this small the mass spectrum is the more informative of the two.
Testing and supply from NuVion
NuVion’s Pinealon comes from GMP-audited manufacture and is supplied lyophilised in sealed vials. Most batches are independently tested by Janoshik Analytical for purity by RP-HPLC and identity by mass spectrometry, and the Certificate of Analysis for a tested batch is published on the product page and in the COA library. Orders are dispatched from within Australia.
Related compounds
Epithalon (Ala-Glu-Asp-Gly) is the tetrapeptide from the same design programme and is studied in telomerase expression and chromatin models, while Semax, an ACTH(4-7)-Pro-Gly-Pro heptapeptide, is the other short peptide in the Neuroscience category used in neuronal cell culture.
Frequently asked questions
What is Pinealon used for in research?
It is used as a tool compound in neuronal cell culture, mainly in oxidative stress and cell survival assays and in gene expression studies that test whether a short charged peptide can alter transcription through direct chromatin interaction. It also serves as a model analyte for hydrophilic peptide chromatography.
Does Pinealon act through a receptor?
No receptor has been identified. The in vitro data point to intracellular actions, including a reduction in ROS accumulation with ERK1/2 activation and a proposed interaction with DNA in the nucleus. Experiments are therefore designed around intracellular readouts and include uptake controls.
Is Pinealon a therapeutic good in Australia?
No. Pinealon from NuVion is a laboratory chemical for in vitro research. It is not included in the Australian Register of Therapeutic Goods and has not been assessed by the TGA. It is not for human or veterinary use.
How should Pinealon be stored?
Keep the lyophilised powder sealed, dry, away from light and refrigerated according to the product documentation. After reconstitution with bacteriostatic water, refrigerate the solution and use it within the period stated in the documentation, since the N-terminal glutamate can slowly cyclise in solution.
Research use only. This product is a laboratory chemical supplied for in vitro research. It is not included in the Australian Register of Therapeutic Goods and has not been assessed by the Therapeutic Goods Administration for quality, safety or efficacy. It is not for human or veterinary use, and nothing on this page is a representation about therapeutic use.
