GHK-Cu (glycyl-L-histidyl-L-lysine copper, CAS 49557-75-7) is a naturally occurring tripeptide-copper complex that has accumulated a significant body of in-vitro research literature around its role in tissue biology. This overview covers what it is, how it works at the molecular level, and what researchers need to know about working with it in a laboratory setting.
Biochemistry and Structure
GHK-Cu consists of three amino acids — glycine, histidine, and lysine — bound to a divalent copper ion (Cu²⁺). The histidine residue is critical for copper coordination, forming a stable 1:1 complex with Cu²⁺. At physiological pH, this complex is highly stable.
The molecular formula is C₁₄H₂₃CuN₆O₄ with a molecular weight of approximately 340 Da, making it one of the smaller peptides studied in tissue remodeling research.
Natural Occurrence and Age-Related Changes
GHK-Cu occurs naturally in human plasma, saliva, and urine. Research has noted that plasma GHK concentrations decline substantially with age: levels in young adults (approximately 200 ng/mL) fall to roughly 80 ng/mL by age 60. This age-associated decline has positioned GHK-Cu as a compound of interest in longevity and tissue maintenance research.
Proposed Mechanisms in Tissue Remodeling
In-vitro laboratory research has explored several mechanisms through which GHK-Cu may influence tissue biology:
- Matrix metalloproteinase (MMP) modulation: Research suggests GHK-Cu may regulate MMP-2 and MMP-9 activity, affecting extracellular matrix remodeling.
- Collagen synthesis: Cell culture experiments have examined GHK-Cu's potential influence on fibroblast collagen production.
- TGF-β pathway interactions: Some studies in fibroblast cultures have explored GHK-Cu's interaction with transforming growth factor pathways.
- Antioxidant activity: The copper component of GHK-Cu participates in superoxide dismutase-like reactions that have been studied in oxidative stress models.
Laboratory Handling and Preparation
Reconstitution
GHK-Cu supplied by Rapid Research CO arrives as a lyophilized powder in 50mg or 100mg vials at ≥99% purity. Reconstitute with bacteriostatic water. The peptide dissolves readily — no extended mixing times are required.
Storage
Lyophilized: store at −20°C, dry, away from light. Reconstituted: store at 4°C, use within 28 days. The copper-peptide complex is stable under these standard peptide storage conditions.
Working Concentrations
Common research concentrations range from 1–10µM in cell culture applications, though your specific protocol will dictate the appropriate concentration for your assay system.
Related Compounds
Researchers studying tissue remodeling alongside GHK-Cu often include:
- NAD+ 500mg — coenzyme studied in cellular energy and aging research
- MOTS-c — mitochondrial-derived peptide studied in metabolic homeostasis