Key findings
- Potentiometry, calorimetry and three spectroscopies resolved several copper complexes of different stoichiometry and stability, including binuclear species, and placed the lysine side chain in the coordination only at alkaline pH. [1]
- The tripeptide forms complexes with copper readily and increased the uptake of the metal into cultured hepatoma cells, which is the observation that framed it as a copper transport factor. [2]
- Two ternary complexes form between the copper peptide and histidine side chains of human serum albumin, with His3 identified as one site and conditional binding constants measured for both. [3]
- In cell and tissue assays the peptide reduced the redox activity of copper, prevented and reversed copper and zinc driven protein aggregation, and raised collagen IV in human dermal fibroblasts and in an ex-vivo skin model. [4][5]
Identity and structure
- Residues that matter for the complex
- Complex formation is driven by the first glycine residue; the histidine residue did not appear to play a specific role when it was substituted, and the free side chain of the lysine residue was of fundamental importance in the cited work [1]
- Free peptide and copper complex are different materials
- At physiological pH the lysine amino group is protonated and outside the coordination, and it enters complex formation only at alkaline pH, so pH and copper ratio decide which species is present [1]
- Partition behaviour
- Distribution coefficients in octanol against phosphate buffered saline were between -2.38 and -2.49 over pH 4.5 to 7.4, indicating a highly hydrophilic material [6]
- Form as supplied
- Sterile lyophilized powder
Mechanism as studied
The equilibrium work is the centre of this profile. Copper complex formation was examined by potentiometry, solution calorimetry, ultraviolet and visible spectrophotometry, circular dichroism and electron paramagnetic resonance, and the ligands formed complexes of differing stoichiometry and stability with evidence for binuclear species. Substituting the histidine residue barely changed the result, while the free lysine side chain proved important, which is the basis for treating the free peptide and a copper-containing preparation as different materials. [1]
Albumin adds a second layer to the same chemistry. The copper peptide binds to imidazole nitrogens of albumin histidine side chains to give two ternary complexes, one of them at His3, with conditional binding constants of 2900 and 1700 per molar at pH 7.4. The authors read this as a route by which the exchangeable copper pool travels. [3]
Where cells were used, the reported effects follow copper handling rather than a receptor. The peptide bound copper and reduced its redox activity, prevented copper and zinc driven aggregation of bovine serum albumin and resolubilised aggregated protein, and enhanced uptake of copper into cultured hepatoma cells. The nanochannel work quantifies the same affinity from the analytical side. [4][2][7]
Research findings
Analytical
- System
- Aqueous solutions of the tripeptide and two synthetic analogues with the histidine residue replaced, plus human serum and a cell growth assay
- Measured
- Copper complex formation equilibria by potentiometry, solution calorimetry, ultraviolet and visible spectrophotometry, circular dichroism and electron paramagnetic resonance; enzymatic stability in human serum; and growth factor activity in vitro
- Reported
- All ligands formed complexes of differing stoichiometry and stability with evidence for binuclear species. The lysine side chain amino group participated in complex formation only at alkaline pH, being protonated at physiological pH. The two synthetic analogues showed no significant degradation in human serum for at least three hours and growth activity comparable to or higher than the parent tripeptide. [1]
In vitro
- System
- Cultured hepatoma cells, with structure-function comparisons across related tripeptides
- Measured
- Cellular responses to the tripeptide added at nanomolar concentrations, co-isolation of the peptide with copper and iron, complex formation with copper, and uptake of the metal into the cultured cells
- Reported
- The peptide co-isolated with approximately equimolar copper and about one fifth molar iron, the largest effects on the hepatoma cells appeared when peptide, copper and iron were added together, several tripeptides carrying a histidyl-lysyl linkage were nearly as active, and the tripeptide formed copper complexes readily and enhanced uptake of the metal into the cells. [2]
Analytical
- System
- Human serum albumin and the tripeptide in solution with copper
- Measured
- Formation, site and stability of ternary copper complexes between the peptide and albumin histidine imidazole nitrogens, with conditional binding constants at pH 7.4
- Reported
- Two ternary complexes formed through imidazole nitrogens of albumin histidine side chains. His3 was identified as one site with a conditional binding constant of 2900 per molar, and the second site, with 1700 per molar, was likely supplied by either His128 or His510. [3]
Analytical
- System
- The copper tripeptide in aqueous solution and buffers, under applied chemical and physical stress, and with candidate formulation components
- Measured
- Solubility and distribution coefficients, content by a validated stability indicating reversed phase HPLC method, degradation under acidic, basic and oxidative stress, identity of degradation products by mass spectrometry, and compatibility with niosome components
- Reported
- The material was susceptible to hydrolytic cleavage under basic and oxidative stress and less so under acidic stress, with first order degradation profiles, yet stable in water and in pH 4.5 to 7.4 buffers for at least two weeks at 60 °C. Three key degradation products were identified, one of them the constituent amino acid histidine. It was compatible with Span 60 based niosomes and less stable in the presence of the negatively charged lipid dicetyl phosphate. [6]
In vitro
- System
- Central nervous system cell cultures exposed to excess copper or zinc, bovine serum albumin aggregation assays, and an inflammatory condition plus a paraquat challenge
- Measured
- Copper redox activity, cell death under copper and zinc load, aggregation and resolubilisation of bovine serum albumin, and toxicity of copper under inflammatory conditions and alongside paraquat
- Reported
- The peptide bound copper and reduced its redox activity, prevented copper and zinc driven cell death, prevented copper and zinc driven aggregation of bovine serum albumin and reversed aggregation by resolubilising the protein. Copper toxicity was enhanced under inflammatory conditions and the peptide attenuated it, and it was also protective against the copper enhanced paraquat toxicity. [4]
In vitro
- System
- Human dermal fibroblast cultures and, for the selected combination, an ex-vivo skin model, with the copper tripeptide tested alone and combined with hyaluronic acid of differing molecular weight
- Measured
- Collagen I, IV and VII expression by quantitative RT-PCR in fibroblasts, and collagen IV content by immunofluorescence in the ex-vivo skin model
- Reported
- The combination raised collagen I, IV and VII, with a synergy specific to collagen IV. At a one to nine ratio with low molecular weight hyaluronic acid, collagen IV rose 25.4 fold in the cell test and 2.03 fold in the ex-vivo skin test. [5]
In vitro
- System
- Human umbilical vein endothelial cells exposed to the copper tripeptide encapsulated in liposomes rather than in free form
- Measured
- Endothelial proliferation rate, cell cycle distribution by flow cytometry, and expression of vascular endothelial growth factor, fibroblast growth factor 2, CDK4 and cyclin D1 by Western blot
- Reported
- The liposome encapsulated material raised endothelial proliferation by 33.1 percent, increased the cell number in G1 and decreased it in G2, and raised vascular endothelial growth factor, fibroblast growth factor 2, CDK4 and cyclin D1. [8]
Preclinical in vivo
- System
- A mouse scald model comparing the liposome encapsulated copper tripeptide against the free complex, reported in the same paper as the endothelial cell work
- Measured
- Angiogenesis in burned skin, with CD31 and Ki67 signal by immunofluorescence
- Reported
- Angiogenesis in burned skin was greater in the liposome arm than in the free complex arm, and the immunofluorescence signal for CD31 and Ki67 was enhanced in the liposome arm. [8]
Handling for in-vitro work
- pH range in cited work
- Stable in water and in pH 4.5 to 7.4 buffers for at least two weeks at 60 °C, and susceptible to hydrolytic cleavage under basic and oxidative stress [6]
- Incompatibility reported
- Less stable in the presence of the negatively charged lipid dicetyl phosphate, and compatible with Span 60 based niosomes [6]
- Competing ligands
- EDTA dissociates the copper peptide complex in the cited nanochannel work, so chelators in a buffer will change which species is present [7]
- Storage
- Lyophilized at -20 °C, dark and dry; reconstituted aliquots kept cold and used promptly
Open questions
- Which copper species is present depends on pH, copper ratio and competing ligands, and the cited equilibrium work does not identify a single species that carries the cell culture results.
- The free tripeptide and a copper containing preparation are different materials, and a listing that gives only a peptide name does not say which was supplied.
- One cited cell study used a liposome encapsulated preparation rather than the free complex, so its numbers belong to that formulation.
- Albumin forms ternary complexes with the copper peptide, so serum in an assay medium changes the speciation the cited solution chemistry describes.
Cosmetic and clinical literature attached to this name concerns finished formulations rather than a research material, and is out of scope for this profile.
Lot records
Check the record for the exact material you order. A published paper and a batch certificate answer different questions.
- RV-24-0039-2 ↗GHK-Cu · 99.30% HPLC2026-09-22
- RV-24-0039-1 ↗GHK-Cu · 99.30% HPLC2026-09-16
References
- Conato C, Gavioli R, Guerrini R, et al. Copper complexes of glycyl-histidyl-lysine and two of its synthetic analogues: chemical behaviour and biological activity. Biochimica et biophysica acta. 2001.
- Pickart L, Freedman JH, Loker WJ, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature. 1980.
- Bossak-Ahmad K, Bal W, Frączyk T, et al. Ternary Cu2+ Complexes of Human Serum Albumin and Glycyl-l-histidyl-l-lysine. Inorganic chemistry. 2021.
- Min JH, Sarlus H, Harris RA Glycyl-l-histidyl-l-lysine prevents copper- and zinc-induced protein aggregation and central nervous system cell death in vitro. Metallomics : integrated biometal science. 2024.
- Jiang F, Wu Y, Liu Z, et al. Synergy of GHK-Cu and hyaluronic acid on collagen IV upregulation via fibroblast and ex-vivo skin tests. Journal of cosmetic dermatology. 2023.
- Badenhorst T, Svirskis D, Wu Z Physicochemical characterization of native glycyl-l-histidyl-l-lysine tripeptide for wound healing and anti-aging: a preformulation study for dermal delivery. Pharmaceutical development and technology. 2016.
- An P, Zhang Z, Yang J, et al. Ultrasensitive and Label-Free Detection of Copper Ions by GHK-Modified Asymmetric Nanochannels. Analytical chemistry. 2023.
- Wang X, Liu B, Xu Q, et al. GHK-Cu-liposomes accelerate scald wound healing in mice by promoting cell proliferation and angiogenesis. Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society. 2017.
Publication records fetched from PubMed on 2026-09-20. Profile text reviewed 2026-09-20.