HEP-1 (Gepon)

What HEP-1 (Gepon) is, structurally

HEP-1 is a peptide of fourteen residues. Its sequence corresponds to a short segment of ezrin, a much larger human protein, which makes the supplied material a defined synthetic fragment rather than the parent protein. The two are different substances with different masses, and only the fragment is what the vial contains.

Two specification fields are empty at source, and one can be filled from the public record. The deposited entry for this CAS gives C74H132N26O27, which computes to 1818.03, the figure the product page approximates as around 1818. The agreement suggests the approximation sign is caution rather than real uncertainty. The sections below are built on that formula, with its external origin stated plainly.

Read that way, the composition is striking. Of twenty-six nitrogens, fourteen are backbone amides, leaving twelve on side chains. Of twenty-seven oxygens, fifteen belong to the backbone carbonyls and the C-terminal acid, leaving twelve. Twelve side-chain nitrogens and twelve side-chain oxygens across only fourteen residues means the molecule is densely charged in both directions: abundant basic side chains and abundant acidic ones. The deposited structure shows guanidine groups, consistent with arginine, which carries three nitrogens each.

It is very hydrophilic and should dissolve readily. Carrying charge of both signs across a wide pH range, it also lacks the narrow band of poor solubility that a singly-ionisable peptide shows near its isoelectric point.

There is no sulfur in the formula, which closes the disulfide and thiol-oxidation questions entirely. No reducing agent is needed.

Reconstitution and handling

Sterile water is the default solvent and should be sufficient. A peptide this polar rarely needs help dissolving; if a vial is slow, warming to room temperature and patience will do more than changing solvent.

Add diluent down the inside wall of the vial, swirl gently, and let the solution clarify. Vortexing introduces foam without dissolving anything faster.

Ordinary neutral buffers are suitable. Carrying both acidic and basic groups, the molecule is less sensitive to buffer pH than one dominated by either, which widens the usable range rather than narrowing it.

This is laboratory preparation chemistry, not dosing, administration, or protocol guidance of any kind.

Storage and stability

Store the lyophilized powder at -20 degrees C, sealed, desiccated and protected from light, and let a cold vial warm before opening so moisture does not condense onto the solid. Reconstituted, hold at 2 to 8 degrees C, or aliquot and freeze rather than thawing repeatedly.

The side-chain nitrogen count is high enough that asparagine or glutamine may sit among the basic residues, and both deamidate to their acidic counterparts, adding about one mass unit each. The reaction needs water, so the dry solid is largely protected while solutions are not. Without a sequence on file this page will not name which positions carry that liability.

Desiccation earns its place here: highly charged lyophilized material draws moisture readily, so an open vial takes up water faster than a less polar peptide would.

These are storage conditions for the material, not dosing or administration guidance.

How HEP-1 (Gepon) is tested

Reversed-phase HPLC establishes chromatographic purity as area percent, and this molecule presents a difficulty worth anticipating. It is small, very polar and densely charged, close to a worst case for retention on a standard C18 column, and should be expected to elute early, possibly near the void volume, where it is poorly separated from salts and other polar material. High-aqueous starting conditions, an ion-pairing mobile phase, or a stationary phase chosen for polar retention are the usual remedies. An unadapted method may give an unrealistically clean result because nothing has been resolved.

The carbon count is low relative to residue count, so detection should be assumed to sit near 214 nm.

Area percent is a chromatographic measure, not peptide content by weight. Solid-phase synthesis delivers a salt, and on a densely charged peptide the counter-ion burden is proportionally significant.

Mass spectrometry confirms identity. On the deposited formula the average mass is 1818.03 and the monoisotopic 1816.98, about one unit apart, close to the shift a single deamidation produces. The two should not be confused: a result near 1817 may reflect the mass convention in use rather than a modification, so establish the reporting basis before interpreting a discrepancy.

These describe general methodology, not a claim about any particular batch.

Handling FAQ

The product page gives the weight as approximately 1818. Is the exact value known? The deposited record for this CAS gives C74H132N26O27, which computes to 1818.03. The product page's approximation is consistent with that, so the uncertainty appears presentational rather than chemical, though the formula is not currently in the database.

Why does this peptide elute so early on a C18 column? Because it is short, very polar and densely charged, giving it little to bind a reversed-phase surface with. Early elution is expected rather than a fault, but a standard gradient may not resolve it properly.

Full specifications for HEP-1 (Gepon).