Livagen 10mg

What Livagen is

Livagen is the trade designation for Lys-Glu-Asp-Ala (KEDA), a linear tetrapeptide of four standard L-residues with an average free-acid mass of about 461 g/mol. Its opening lysine sets it apart from the rest of our short-peptide group: every other member is either purely acidic or carries its basic residue at the C-terminal end, while Livagen puts a primary-amine side chain right at the front.

Its last three residues, Glu-Asp-Ala, use the same amino acids as the Ala-Glu-Asp core shared by Cartalax, Epithalon, Cortagen and Cardiogen, but in a different order. Residue order defines a peptide, so KEDA is not a variant of that set in any useful sense. It is a separate molecule with its own mass, its own charge profile and its own chromatographic behavior, and it is verified by sequence and mass rather than by name.

Livagen 10mg specification

How Livagen is analyzed

With the lysine side-chain amine and the N-terminal amine on one side, and two carboxylate side chains plus the C-terminal acid on the other, KEDA is zwitterionic across most of the working pH range, and its retention moves noticeably with mobile-phase pH. The basic amines can also interact with residual silanols on silica-based C18 packing, which appears as tailing; an ion-pairing additive such as trifluoroacetic acid is what keeps the peak shape honest, so the additive named in the method matters when judging the trace. Carrying two amines, the molecule protonates readily in electrospray and may show a doubly charged ion near m/z 232 alongside the singly charged ion just above 461. There is no aromatic ring, so quantitation is done in the 214 nm region.

Livagen’s own reverse-phase HPLC result sits on this page. No lot or batch identifier is printed on the vials; a Livagen vial’s crimp and cap color points to the specific published test it belongs with.

Research contexts for Livagen

• Silanol-interaction and ion-pairing studies with a short lysine-containing peptide
• Chromatin-binding assays in cell-free systems with purified histones
• Electrospray charge-state distribution work on small zwitterionic peptides
• Sequence-order comparisons between KEDA and the Ala-Glu-Asp group

Livagen is sold solely as a reagent for in-vitro and analytical research, not for use in any living person or animal.

Livagen questions

Does a tailing Livagen peak mean the sample is impure?

Not necessarily. Lysine interacting with free silanols on the column produces tailing that reflects the method rather than the material. Check which ion-pairing additive was used before reading tailing as contamination.

Why might the Livagen spectrum show an ion near m/z 232?

That is the doubly protonated molecule. With two amine groups, KEDA picks up a second proton easily, so an [M+2H]2+ ion at roughly half the mass is expected next to [M+H]+.

Is Livagen related to the Ala-Glu-Asp peptides?

Only loosely. It contains the same three amino acids as that core, but in a different order and with a lysine in front, so its mass, charge and retention are all its own.