ARA-290, also called cibinetide or pyroglutamate helix-B surface peptide, is an 11-residue peptide derived from the solvent-exposed face of erythropoietin helix B. It was designed to study tissue-protective EPO signalling without the erythropoietic activity of the full glycoprotein.
What Are the Key ARA-290 Research Specifications?
| Specification | Research record |
|---|---|
| Compound | ARA-290 |
| Category | misc |
| Listed purity | >99% |
| Molecular weight | 1317.4 g/mol for the acetate form |
| Intended use | Laboratory research only |
What Is the Chemical Identity of ARA-290?
The free peptide sequence is pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser (pEQLERALNSS). The N-terminal pyroglutamate is a defined modification, not an incidental degradation product. PubChem lists the acetate form at 1317.4 g/mol; free peptide and other counterion forms have different formula masses. An “approximately 1.0 kDa” description is therefore too imprecise for molar work.
What Does the Evidence Say About ARA-290?
ARA-290 was developed from the hypothesis that a tissue-protective receptor complex contains EPOR and the beta-common receptor CD131. Studies have linked the peptide to anti-inflammatory and repair-associated signalling without stimulation of red-cell production. The receptor model remains debated: biochemical work has not consistently demonstrated a direct EPOR–CD131 complex. Researchers should present it as a working model rather than settled receptor pharmacology.
Published work spans cell systems, injury models and small clinical investigations. For mechanistic laboratory studies, the most informative readouts are receptor dependence, proximal phosphorylation events, inflammatory mediators and phenotype rescue in cells lacking EPOR or CD131.
How Should a ARA-290 Study Be Designed?
Include full-length EPO and an inactive or scrambled peptide control. If the innate-repair-receptor hypothesis is central, use receptor knockout, knockdown or blocking reagents. Record the species and receptor expression of the model: apparent inactivity may reflect receptor context rather than peptide instability.
How Should ARA-290 Be Handled and Verified?
Confirm the pyroglutamyl N-terminus, intact mass and counterion. Acidic peptides may adsorb differently as buffer pH and ionic strength change, so perform recovery checks at the working concentration. Use low-binding tubes, single-use aliquots and a stability time course in the assay matrix. For cell work, document endotoxin independently of HPLC purity.
Which Sources Support ARA-290 Research?
- Brines and colleagues’ overview of ARA-290 and the innate repair receptor, PMID 29392190.
- Cheung Tung Shing et al., evidence challenging direct EPOR–CD131 association, Scientific Reports (2018), PMID 30127368.
How Can ARA-290 Results Be Interpreted Without Overclaiming?
The strongest ARA-290 evidence connects identity to mechanism to phenotype in that order. For ARA-290, chemical identity, target engagement and downstream phenotype are separate layers. A change in migration, viability or gene expression does not by itself prove the proposed molecular target. A useful study includes an orthogonal analytical identity check, a target-dependent perturbation and a second assay that measures the same biology by a different method. This design makes a positive result easier to reproduce and a negative result easier to interpret.
For citation-ready ARA-290 reporting, provide raw concentration units, biological replicate counts, prespecified exclusions and the exact time point. Separate exploratory endpoints from confirmatory ones. If exposure was not measured, describe potency as nominal rather than intracellular or free concentration. Limit the conclusion to the model used; avoid converting a pathway observation into a claim about clinical benefit.
Is ARA-290 for Research Use Only?
ARA-290 is supplied for laboratory research only. It is not for human or veterinary use.
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What Are Common Questions About ARA-290?
What is ARA-290?
ARA-290, also called cibinetide or pyroglutamate helix-B surface peptide, is an 11-residue peptide derived from the solvent-exposed face of erythropoietin helix B. It was designed to study tissue-protective EPO signalling without the erythropoietic activity of the full glycoprotein.
How should researchers verify ARA-290?
Confirm the exact molecular form on the lot certificate and pair chromatographic purity with an orthogonal identity method such as mass spectrometry or NMR. Use the molecular weight, counterion and content stated for that verified form when calculating molarity.
Is ARA-290 intended for human use?
ARA-290 is listed for controlled laboratory research only. It is not intended for human or veterinary use.