Cardiogen is the synthetic tetrapeptide Ala-Glu-Asp-Arg (AEDR), a member of the Khavinson short peptide bioregulator series. Four residues and a molecular weight of 489 g/mol place it in the same structural family as Epithalon and Bronchogen, and it is used in cell-based studies of sequence-preferential DNA binding and of cytoskeletal and nuclear matrix protein expression in cardiac cell models. NuVion supplies Cardiogen as a laboratory chemical for in vitro research use only.
Key facts
| Type | Synthetic tetrapeptide bioregulator |
| Amino acid count | 4 |
| Sequence | H-Ala-Glu-Asp-Arg-OH (AEDR) |
| Molecular formula | C19H33N7O8 |
| Molecular weight | 489.5 g/mol |
| Series | Khavinson short peptide bioregulators |
| Synonyms | AEDR, Ala-Glu-Asp-Arg, cardiogen tetrapeptide |
| Supplied form | Lyophilised powder in a sealed vial |
Cardiogen (AEDR)
$109 AUD
View productResearch use only. Not for human or veterinary use.
Structure and chemistry
Cardiogen is a linear tetrapeptide carrying two acidic side chains, from glutamate and aspartate, and one strongly basic side chain from the C-terminal arginine. The guanidinium group of arginine holds a positive charge across the whole physiological pH range, so the molecule is zwitterionic with an internal charge pair and a net charge near minus one. That arrangement of charges is the structural feature that separates Cardiogen from the rest of the series and the one most often invoked in binding models, because a guanidinium group is well suited to bidentate hydrogen bonding with the phosphate backbone and with guanine in the major groove of DNA.
Within the Khavinson set the sequences are deliberately close. Epithalon is Ala-Glu-Asp-Gly, Bronchogen is Ala-Glu-Asp-Leu and Cardiogen is Ala-Glu-Asp-Arg, so all three share the acidic Ala-Glu-Asp core and vary only at position four. Pinealon, the tripeptide Glu-Asp-Arg, is the C-terminal three residues of Cardiogen without the N-terminal alanine, which makes the two a useful pair for asking whether the additional residue changes binding preference or stability.
The peptide contains no oxidisable residue and no N-terminal glutamate, so neither photo-oxidation nor pyroglutamate formation is a significant route of degradation. Arginine can undergo slow deamidation-like side reactions under strongly alkaline conditions, which is a reason to keep stock solutions near neutral pH. In serum-containing medium the dominant loss is aminopeptidase cleavage from the alanine terminus. Purity is determined by RP-HPLC and identity by mass spectrometry, with the singly protonated parent at m/z 490 and a characteristic arginine immonium fragment in MS/MS.
Mechanism of action
No receptor has been identified for Cardiogen. The mechanism described in the literature from the group that developed the series is a direct interaction with DNA at the level of the duplex, with no signalling cascade proposed. Short peptides of this composition are proposed to reach the nucleus and associate with the major groove at particular short motifs, with the arginine guanidinium making the sequence-discriminating contact and the acidic residues positioning the backbone. Molecular dynamics simulations, circular dichroism and duplex melting experiments have been used to argue for preferential association with CNG-containing sequences and for sensitivity to the methylation state of the central cytosine. The proposal remains a hypothesis, and no established transcriptional pathway has been mapped behind it.
What is measured in cell systems is downstream expression. In cardiomyocyte and cardiac fibroblast cultures, exposure to AEDR has been reported to alter transcript and protein levels of cytoskeletal and nuclear matrix components, including sarcomeric and lamin-associated proteins, read by qPCR, immunofluorescence and Western blot over hours to days. The related tripeptide Pinealon has been examined in parallel in neuronal culture with comparable endpoints, and the two are often run together so that the contribution of the extra alanine can be assessed. Because the tetrapeptide is cleaved quickly by aminopeptidases, experiments in serum-containing medium generally use repeated exposure or serum-reduced conditions.
Research applications
- DNA interaction studies with short synthetic duplexes: circular dichroism, thermal denaturation and electrophoretic mobility shift assays across methylated and unmethylated CNG motifs.
- Gene and protein expression profiling in cardiomyocyte and cardiac fibroblast culture by qPCR, immunofluorescence and Western blot.
- Structure-activity comparison across the Khavinson series, varying only the residue at position four under identical assay conditions.
- Paired comparison with the tripeptide Pinealon to test the contribution of the N-terminal alanine to binding and stability.
- Peptidase stability assays in serum and cell lysate, following loss of the parent by LC-MS.
- Reference standard for RP-HPLC and LC-MS method development on short basic-acidic peptides.
Cardiogen sits in NuVion’s Immune Signalling category with the other short peptide bioregulators.
Handling in the laboratory
Cardiogen is supplied lyophilised and is reconstituted with bacteriostatic water added slowly to the vial and swirled until dissolved. Solubility in water is high and no organic co-solvent is required. The reconstitution calculator converts vial content and diluent volume into a stock concentration. Stock for cell work is diluted into buffered medium so that the acidic free peptide does not shift the pH of the culture, and a vehicle control accounts for the benzyl alcohol carried over from the diluent.
Unopened vials are kept sealed, dry and refrigerated as stated on the product documentation. Reconstituted solution is refrigerated and used within the period given there, or aliquoted and frozen to avoid repeated freeze-thaw cycles. Solutions are kept near neutral pH in storage, since prolonged alkaline conditions are the main chemical risk to the arginine side chain.
Testing and supply from NuVion
NuVion’s Cardiogen is manufactured at a GMP-audited facility and independently tested by Janoshik Analytical, with purity determined by RP-HPLC and identity confirmed by mass spectrometry. The Certificate of Analysis for a tested batch is published on the product page and in the COA library. The peptide is supplied lyophilised in sealed vials and dispatched from within Australia.
Related compounds
Closely related sequences include Pinealon (Glu-Asp-Arg), which is Cardiogen without its N-terminal alanine, plus Epithalon and Bronchogen, which differ only at position four.
Frequently asked questions
What is Cardiogen used for in research?
It is used as a defined tetrapeptide in DNA-binding experiments with short synthetic duplexes, in gene and protein expression work in cardiac cell culture, and as one member of a structure-activity series across the Khavinson short peptides.
How does Cardiogen relate to Pinealon?
Pinealon is the tripeptide Glu-Asp-Arg, which is the C-terminal three residues of Cardiogen. Running the two together under the same conditions isolates the contribution of the N-terminal alanine to binding preference and to peptidase stability.
Is Cardiogen a therapeutic good in Australia?
No. NuVion’s Cardiogen is a laboratory chemical for in vitro research. It is not included in the Australian Register of Therapeutic Goods, has not been assessed by the Therapeutic Goods Administration, and is not for human or veterinary use.
How should Cardiogen be stored?
Lyophilised vials are kept sealed, dry and refrigerated per the product documentation. Reconstituted solution is refrigerated and used within the stated period, or aliquoted and frozen, and is held near neutral pH.
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.
