ARA-290

For Laboratory Research Use Only — Not for Human or Veterinary Use.

Standard (< 1,000 vials)$260/kit

Volume (1,000+ vials)$190/kit

Quantity (kits)

= 10 vials

Minimum order: 100 vials total. Mix and match across all products.

I confirm this order is for laboratory research use only.For Laboratory Research Use Only — Not for Human or Veterinary Use. By checking this box you affirm this product will not be used for human or animal administration.

Specifications

CAS Number	1208243-50-8
Molecular Formula	C51H84N16O21
Molecular Weight	1257.32 g/mol
Purity	≥98% (HPLC)
Form	Lyophilized Powder
Storage	-20°C, desiccated, protected from light
Reconstitution	Bacteriostatic water

Certificate of Analysis

Lot documentation

Every production lot is independently third-party tested. A batch-specific Certificate of Analysis — documenting HPLC purity, mass spectrometry identity confirmation, and net peptide content — is issued with every shipment. View a sample COA to see the format.

View Sample COA About our testing →

Research context

An eleven-residue peptide derived from a structural helix of erythropoietin, engaging a receptor complex distinct from the classical erythropoietin receptor. Supplied lyophilised.

Structure and molecular target

ARA-290, known by the international nonproprietary name cibinetide, is an eleven-residue linear peptide corresponding to a solvent-exposed region of helix B of erythropoietin. It reproduces a surface of the parent protein rather than a contiguous functional domain, which is an unusual design and central to what the molecule is for.

Erythropoietin engages two distinct receptor assemblies. The classical homodimeric receptor drives erythropoiesis; a separate heteromeric complex of the erythropoietin receptor with the beta common receptor subunit, described in the literature as the innate repair receptor, is associated with tissue-protective signalling. This peptide was designed to engage the latter without engaging the former, and it is reported as non-erythropoietic in the relevant assay systems.

Findings in the published research literature

The defining experiment for this compound is a negative one: demonstrating absence of erythropoietic activity while retaining signalling through the heteromeric complex. Colony-forming assays on erythroid progenitors are the standard system for establishing that separation, and a report of this peptide without that control is incomplete.

Downstream work uses cultured neuronal and immune cell preparations examining signalling through the heteromeric receptor, with rodent models of nerve injury and inflammation forming much of the in vivo literature. The mechanistic question that recurs is how a short linear peptide reproduces a conformational epitope of a folded protein well enough to discriminate between two receptor assemblies.

Analytical verification

An eleven-residue linear peptide with no cysteine, no terminal modification and no unnatural residue is straightforward to synthesise and verify. Reversed-phase HPLC establishes purity and mass spectrometry confirms identity, reported per lot on the Certificate of Analysis, with deletion sequences from incomplete coupling the principal impurity class.

The characterisation that actually matters for this molecule cannot be established by a Certificate of Analysis at all. Its defining property is receptor selectivity, and that is a functional attribute demonstrated by cell-based assay rather than a chemical one, so a purity figure confirms the correct sequence is present without speaking to the property the compound exists for.

Handling and storage

Solubility	Soluble in water and neutral aqueous buffer.
Reconstitution	Dissolves readily with gentle swirling.
Storage	Lyophilised powder at -20C, desiccated. Reconstituted solution at 2-8C.
Stability	Chemically robust, with no oxidation- or disulfide-prone residues. Freeze-thaw cycling of reconstituted material is the main practical concern.