AHK-Cu (Copper Tripeptide-3) vs Pinealon (EDR)

AHK-Cu (Copper Tripeptide-3)

AHK-Cu is a copper(II) complex of the synthetic tripeptide alanyl-histidyl-lysine, a close relative of the naturally occurring GHK-Cu. The two differ only in the first residue: alanine here, glycine in GHK. GHK is found in human plasma and has a long history in the literature as a copper-binding peptide; AHK is a synthetic variant with the histidine in the same position. Published work on AHK-Cu is small and mostly in vitro, using cultured human dermal papilla cells and fibroblasts, and isolated hair follicles kept alive in organ culture. Controlled human studies are scarce, and much of the wider discussion of the compound borrows from GHK-Cu rather than from data on AHK-Cu itself.

Pinealon (EDR)

Pinealon is the synthetic tripeptide Glu-Asp-Arg (EDR), one of the short 'bioregulator' peptides described by a Russian research group. That group proposes that very short peptides can act on gene expression directly, without a conventional receptor, a view that has had little independent testing. Most published work on Pinealon comes from the same group and its collaborators. It consists of experiments in cultured neurons and other cells, rodent studies centred on the nervous system and oxidative stress, and computer modelling of how the peptide might bind DNA. Human data are very limited.

How AHK-Cu (Copper Tripeptide-3) acts

In GHK-Cu, the copper ion is held by the N-terminal amine, the deprotonated amide nitrogen between the first two residues and a nitrogen of the histidine imidazole ring. AHK is thought to bind copper in the same way, since its histidine sits in the same position. Copper-peptide complexes of this kind have been studied as carriers that deliver copper, a cofactor for enzymes such as lysyl oxidase and superoxide dismutase, to cells. In cultured human dermal papilla cells, AHK-Cu has been reported to affect cell proliferation and markers of apoptosis, including the balance of Bcl-2 and Bax. Which receptors or transporters mediate these observations has not been established.

How Pinealon (EDR) acts

The originating group has proposed that EDR enters cells and their nuclei and binds particular DNA sequences or histone proteins, changing the expression of nearby genes. Support for this comes mainly from molecular modelling and in vitro binding experiments. In cultured neurons and other cells exposed to oxidative stress, Pinealon has been reported to lower the accumulation of reactive oxygen species and to alter ERK1/2 (MAPK) signalling, and rodent studies from the same group have measured markers of oxidative damage in brain tissue. No specific receptor for the peptide has been identified, and independent confirmation of these mechanisms is limited.

The records side by side

• Type: AHK-Cu (Copper Tripeptide-3), Copper tripeptide complex; Pinealon (EDR), Tripeptide
• Length: AHK-Cu (Copper Tripeptide-3), 3 amino acids; Pinealon (EDR), 3 amino acids
• Molecular weight: AHK-Cu (Copper Tripeptide-3), 451.39 g/mol; Pinealon (EDR), 418.40 g/mol
• Molecular formula: AHK-Cu (Copper Tripeptide-3), C15H24ClCuN6O4-; Pinealon (EDR), C15H26N6O8

Reading a comparison

A comparison places two records side by side; it does not merge them. Each description above is drawn from that compound's own record, and the two were not necessarily characterised by the same methods, at the same time, or to the same level of detail. Before comparing any attribute, it is worth establishing that both records describe the substance you think they describe — names are not identifiers, and two entries sharing a name can differ in salt form, stereochemistry or the convention used to state a mass. Where a figure carries no method beside it, the comparison is between two reported numbers rather than between two measurements.