What Is Cardiogen?
Short answer: Cardiogen is a short synthetic peptide, the tetrapeptide Ala-Glu-Asp-Arg, written AEDR in one-letter code. It is C18H31N7O9, 489.5 g/mol, with its own PubChem record (CID 11583989). Researchers who want to buy Cardiogen as a reference material get 20 mg of lyophilized powder in a sealed vial, for laboratory research only.
Let’s take this one step at a time. A tetrapeptide sounds like a big word, but it is simply four amino acids holding hands in a row. In Cardiogen those four are L-Alanine, L-Glutamic acid, L-Aspartic acid and L-Arginine. The order matters, the same way the order of letters matters in a word. And as we will see, Cardiogen is really a familiar three-letter word with one new letter written in front of it.
What is Cardiogen, chemically speaking?
PubChem lists Cardiogen as C18H31N7O9 with a molecular weight of 489.5 g/mol and an exact mass of 489.2183 Da. Its four stereocenters are all in the natural L (S) form, and its InChIKey, QXQARLZWUIQZPX-NAKRPEOUSA-N, is the short fingerprint chemists use to make sure two records describe the very same molecule.
PubChem’s computed properties tell a clear story. With an XLogP3 of −6.3, a polar surface area of 290 Å2, 9 hydrogen-bond donors and 11 acceptors, Cardiogen is a very water-loving molecule. That is what you would expect from a peptide carrying three carboxylic acid groups, a free amine and the guanidino group of Arginine.
A quick word about the name
Reading the sequence: A, E, D, R
Here is a simple way to read AEDR from left to right. A is Alanine, the quiet one, with nothing more than a small methyl group on its side. E is Glutamic acid and D is Aspartic acid; both carry carboxylic acids, so they lean negative in neutral water. R is Arginine, whose long side chain ends in a guanidino group that holds on to a positive charge.
Put those together and you have a mixed-charge peptide: a small, neutral residue up front, two acidic residues in the middle and a strongly basic residue at the end. Counting the free amine at the start and the free acid at the finish, a textbook estimate puts its net charge near −1 at neutral pH. That is an estimate from the structure, not a measured value.
How is Cardiogen related to Pinealon?
Cardiogen has a close relative in the catalog. Pinealon is the tripeptide Glu-Asp-Arg, and those three residues are exactly the last three of Cardiogen. Put one L-Alanine in front of Pinealon and you have Cardiogen. In chemistry terms, that adds C3H5NO to the formula and about 71 g/mol to the mass, the mass of one Alanine residue.
Cardiogen also has cousins that share its front end. Cartalax is Ala-Glu-Asp, the first three letters of Cardiogen with nothing after them, and Bronchogen is Ala-Glu-Asp-Leu, the same start with a Leucine at the end instead of an Arginine. So Cardiogen sits right where two families meet. Our post What Is Pinealon? The Glu-Asp-Arg (EDR) Tripeptide Explained covers the shorter sequence in detail.
What do docking studies predict for Cardiogen?
In 2023, Khavinson and colleagues used computer docking to estimate how 26 ultrashort peptides fit into four transporter proteins, LAT1, LAT2, PEPT1 and PEPT2. Docking does not measure anything in a test tube; it scores how well a molecule’s shape and charges match a binding pocket, and more negative ICM-Scores mean a better predicted fit (Khavinson et al., 2023).
Cardiogen did well. It ranked 3rd of 26 at LAT1 with an ICM-Score of −35.35, a more favorable score than every reference ligand the authors tested there, including the potent inhibitor JPH203 (−31.50), L-Leucine (−23.96) and BCH (−17.37). It also ranked 3rd at PEPT1 (−27.50), level with the strongest reference compound (−27.74), and 7th at LAT2 (−27.54). The authors call their PEPT2 scores preliminary, so those are left out here.
The Ala-Glu-Asp family makes a tidy experiment on paper, because the only thing that changes is what follows Aspartic acid:
| Sequence | Peptide | LAT1 ICM-Score | PEPT1 ICM-Score |
|---|---|---|---|
| AED | Cartalax, Ala-Glu-Asp (no fourth residue) | −28.14 | −18.95 |
| AEDR | Cardiogen, Ala-Glu-Asp-Arg | −35.35 | −27.50 |
| AEDG | Ala-Glu-Asp-Gly | −32.93 | −18.00 |
| AEDL | Bronchogen, Ala-Glu-Asp-Leu | −25.11 | −25.35 |
| AEDP | Ala-Glu-Asp-Pro | −20.95 | −12.65 |
Of the five, the Arginine ending gave the best predicted fit at both transporters. The authors observed that the strongest ligands in the survey tend to carry a neutral or positively charged residue at the C-terminus, and Arginine is the positively charged example. A reasonable inference is that the guanidino group helps anchor the peptide in each pocket, although the paper does not test that idea directly.
The same survey also tells us something about the Alanine at the front. Pinealon’s EDR, which lacks that Alanine, was the best-scoring peptide of all 26 (−45.32 at LAT1 and −37.59 at PEPT1). Adding the Alanine moved both scores about ten units in the less favorable direction, yet Cardiogen still finished 3rd at both. One extra letter changed the score but not the company it keeps.
What do binding assays show?
Docking is a prediction. For a measurement, we can turn to a 2013 study by Fedoreyeva and colleagues. They attached a fluorescent tag (FITC) to histones H1, H2B, H3 and H4, the spool proteins that DNA wraps around, and watched the glow dim, a signal called quenching, as short peptides bound to them. AEDR was one of six peptides that bound all four histones, along with AEDG, EDR, AEDL, KEDG and KEDW (Fedoreyeva et al., 2013).
The binding was traced to the N-terminal tails of the histones, and it depended on both the histone and the peptide sequence, which the authors describe as site specific. A 2021 systematic review adds that AEDR is among the short peptides that can either slow or speed up the cutting of λ phage DNA by two endonucleases, WEN1 and WEN2, depending on whether the DNA is methylated (Khavinson et al., 2021).
What formats is Cardiogen supplied in for research?
Modern Aminos offers Cardiogen in one laboratory format: 20 mg of lyophilized powder in a sealed vial. There is no amide cap, so the chain ends in a free carboxylic acid on Arginine. Researchers who want to buy Cardiogen 20mg will find the full identity table, including the InChI and SMILES, on the product page.
What does the current certificate show?
All applicable tests are performed on our products. The current third-party Freedom Diagnostics Testing certificate is published in the product’s Certificate of Analysis tab. It reports chemical analysis by HPLC with UV detection coupled with mass spectrometry, a mass identification for Cardiogen, an endotoxin screen and the appearance of the powder, and upcoming batches receive expanded testing across two ISO-certified labs, covering Sterility, Identity, Purity, Endotoxin, Heavy Metals, Mass, Residual Solvents, Fentanyl and Conformity. Our note on HPLC testing explains why chromatographic testing matters for reference materials like this one.
Where does Cardiogen sit among other short peptide bioregulators?
In the 2023 docking survey, the three best LAT1 scores all belong to peptides sold as bioregulators: Pinealon (EDR) first, Chonluten (Glu-Asp-Gly) second and Cardiogen third. Livagen (Lys-Glu-Asp-Ala) came 11th, and Prostamax (Lys-Glu-Asp-Pro), which our post What Is Prostamax? The Lys-Glu-Asp-Pro (KEDP) Tetrapeptide Explained explains, ranked 2nd at PEPT1.
Frequently asked questions
What is Cardiogen?
Cardiogen is the synthetic tetrapeptide Ala-Glu-Asp-Arg (AEDR), C18H31N7O9 at 489.5 g/mol, PubChem CID 11583989.
Is Cardiogen a peptide?
Yes. Cardiogen is four L-amino acids joined by three peptide bonds, which makes it a tetrapeptide, one of the short peptide bioregulators two to seven residues long.
What are the ingredients of Cardiogen?
Chemically, its four building blocks are L-Alanine, L-Glutamic acid, L-Aspartic acid and L-Arginine, linked in that order from the free amine end to the free carboxylic acid end.
How is Cardiogen different from Pinealon?
Pinealon is Glu-Asp-Arg. Cardiogen is the same three residues with one L-Alanine added at the front, which adds C3H5NO and 71 g/mol to the formula.
What formats does Modern Aminos offer for Cardiogen?
Modern Aminos offers Cardiogen as 20 mg of lyophilized powder in a sealed vial, with a third-party Freedom Diagnostics Testing certificate in the product’s Certificate of Analysis tab.
References
- Khavinson VK, Linkova NS, Rudskoy AI, Petukhov MG. Feasibility of transport of 26 biologically active ultrashort peptides via LAT and PEPT family transporters. Biomolecules. 2023;13(3):552. PMC10046148
- Fedoreyeva LI, Smirnova TA, Kolomijtseva GY, Khavinson VKh, Vanyushin BF. Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides. Biochemistry (Moscow). 2013;78(2):166-175. PubMed 23581987
- Khavinson VK, Popovich IG, Linkova NS, Mironova ES, Ilina AR. Peptide regulation of gene expression: a systematic review. Molecules. 2021;26(22):7053. PMC8619776
- National Library of Medicine. PubChem Compound Summary for CID 11583989, H-Ala-Glu-Asp-Arg-OH. https://pubchem.ncbi.nlm.nih.gov/compound/11583989.
- National Library of Medicine. PubChem Compound Summary for CID 10273502, Glu-Asp-Arg. https://pubchem.ncbi.nlm.nih.gov/compound/10273502.
Cardiogen is a good reminder that in short peptides, one letter can change the whole sentence: write an Alanine in front of Pinealon’s Glu-Asp-Arg and you get a new molecule with its own formula, its own record and its own place in the docking tables. For the certificate, the format and the full chemical specification table, start at the Cardiogen product page.