CJC-1295 (No DAC)

What CJC-1295 (No DAC) is, structurally

This is a twenty-nine-residue peptide corresponding to the first twenty-nine positions of a longer natural sequence, with four of those positions substituted. The alternative name, Modified GRF(1-29), states that construction more plainly than the primary one does.

The residue list is not held in the product database. PubChem's systematic name for this CAS begins L-tyrosyl-D-alanyl-L-alpha-aspartyl-L-alanyl-L-isoleucyl-L-phenylalanyl, which establishes the opening residues and one specific feature of them.

That feature is the D-alanine at position two. Every other residue in that opening is ordinary L-configuration, so this is a deliberate single-position inversion rather than a general property. It sits directly adjacent to the N-terminus, the end an aminopeptidase works from, and a chain is not a substrate for those enzymes at an inverted centre.

The formula settles the sulfur question immediately: there is none. With no sulfur atom at all, the molecule carries neither cysteine nor methionine, which removes disulfide formation, thiol oxidation and sulfoxide formation in one step. That is a cleaner oxidative profile than most peptides of comparable size.

Composition is otherwise hydrophilic. Forty-four nitrogens across twenty-nine residues means fifteen side-chain nitrogens beyond the backbone, consistent with the arginine, lysine and glutamine the systematic name lists. Two tyrosines and a phenylalanine fall within the first ten positions. It is water soluble, though no quantitative figure is quoted here.

Reconstitution and handling

Sterile water is the default solvent, and with no metal centre present PBS or an assay buffer are equally reasonable. Add diluent down the vial wall, swirl gently, and let it clarify. Do not vortex: a chain this length has conformational structure to lose, and foaming promotes aggregation.

No reducing agent is needed, and none should be added out of habit. With no cysteine in the molecule there is nothing for it to act on, so it adds a reactive species to the preparation for no benefit.

Adsorption is worth allowing for at low concentration, and low-protein-binding tubes reduce measured loss. At around 3400 g/mol this peptide presents far more surface than the short peptides here, so the effect is proportionally larger.

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 reach room temperature before opening. Reconstituted, hold at 2 to 8 degrees C for short-term work, or aliquot and freeze rather than thawing repeatedly. A chain of this length has structure to lose on cycling, so aliquot before the first freeze.

With sulfur absent, the remaining liabilities are hydrolytic rather than oxidative. The systematic name places an aspartate at position three and a glutamine at position eight. Aspartyl residues cyclise and reopen as isoaspartate at unchanged mass; glutamine deamidates to glutamate, which does shift the mass by about one unit. Warmth and pH away from neutral accelerate both, and air exposure affects neither.

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

How CJC-1295 (No DAC) is tested

Reversed-phase HPLC establishes chromatographic purity as area percent. Two tyrosines and a phenylalanine give usable absorbance near 280 nm alongside the low-UV amide measurement at 214 nm, so both detection channels are genuinely available rather than nominally so.

Area percent is a chromatographic measure and not peptide content by weight. Solid-phase synthesis delivers a salt, commonly trifluoroacetate or acetate, which lies outside the molecular weight above. Residual trifluoroacetate, truncated chains and deletion sequences are the impurity classes to resolve, and on a twenty-nine-residue chain a single deletion is a small proportional mass change that demands a capable separation.

Mass spectrometry confirms identity against the expected weight. The compound-specific point is what is absent: with no sulfur there is no oxidation satellite to expect, so a peak sixteen units above the molecular ion would mean something other than the usual methionine or cysteine oxidation and is worth investigating. Glutamine deamidation gives about one unit and needs adequate resolution to separate from the isotope envelope.

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

Handling FAQ

Does this need a reducing agent in the buffer? No, and adding one is pointless here. The formula contains no sulfur, so there is no cysteine and no disulfide for a reducing agent to act on. It would simply introduce a reactive species into the preparation.

What would a peak sixteen mass units above the main one mean? Not the usual thing. On most peptides that satellite indicates methionine or cysteine oxidation, but this molecule contains neither, so a plus-sixteen species points to some other oxidation and is worth investigating rather than being written off as routine.

Full specifications for CJC-1295 (No DAC).