The two-residue peptides
At the other end of the shelf from the GLP-1 analogues sit chains of two, three and four amino acids. Almost everything about them is different.
Vilon is lysine and glutamate. Two residues. It is the shortest thing in this catalog and it is a useful object lesson in how little the word "peptide" constrains.
Why they are cheap
One coupling cycle instead of forty. Almost no deletion sequences to purify away, because there is almost nowhere for a deletion to happen. Yields that a forty-residue synthesis would never see. The price difference between the short end of this shelf and the long end is not margin; it is work.
The Khavinson series
Several of the short peptides here — vilon, testagen, pinealon, vesugen — come from a Russian research program into very short peptide sequences, and they are related by construction: vilon is KE, vesugen is KED, testagen is KEDG. Each is the one before it with a residue added.
What gets harder, not easier
- Analysis. A dipeptide is small, polar and poorly retained on a reversed-phase column, so the method that resolves a forty-mer beautifully may barely separate this from the solvent front.
- Mass confirmation. At two hundred and seventy-five grams per mole there is a great deal else in that region of the spectrum.
- Net peptide content. Counter-ions are a much larger fraction of the dry weight when the peptide itself is tiny, so the gap between label weight and peptide weight is at its widest here.
Common questions
How are vilon, vesugen and testagen related?
They are related by construction. Vilon is KE, vesugen is KED and testagen is KEDG, so each is the one before it with a residue added. Along with pinealon, they come from a Russian research program into very short peptide sequences.
What is vilon made of?
It is lysine and glutamate, two residues, written KE. That makes it the shortest thing in this catalog, at two hundred and seventy-five grams per mole, and a useful example of how little the word peptide constrains.
Why do very short peptides cost less than long ones?
They cost less because they are less work. A dipeptide needs one coupling round instead of forty, leaves almost no deletion sequences to purify away, and reaches yields a forty-residue synthesis would never see. The price difference between the short and long ends of the shelf is work, not margin.
Are dipeptides easier to test than long peptides?
No. A dipeptide is small, polar and poorly retained on a reversed-phase column, so the method may barely separate it from the solvent front. Its mass sits in a crowded region of the spectrum, and counter-ions are a much larger fraction of the dry weight, so the gap between label weight and peptide weight is at its widest.
For laboratory research use only. Not a drug, not a supplement, and nothing here is a claim about what any of this material does in a person or an animal.
