Cosmetic · Synthetic extracellular-matrix-associated tetrapeptide
Tetrapeptide-21
Also known as GEKG; Gly-Glu-Lys-Gly
GEKG is a four-residue peptide studied for extracellular-matrix-related responses in dermal fibroblast cultures.
- Length
- 4 amino acids
- Half-life
- Not well characterised
- Mechanism
- GEKG has been investigated for modulation of extracellular-matrix-related gene and protein expression in dermal fibroblast models. A specific directly bound receptor and a fully resolved signalling mechanism have not been established.
- Studied in
- Published laboratory work includes cultured dermal fibroblasts examining collagen-associated endpoints, fibronectin and other extracellular-matrix markers.
About Tetrapeptide-21
Tetrapeptide-21 is commonly identified as Gly-Glu-Lys-Gly, abbreviated GEKG. Its sequence contains glycine at both termini, with glutamate and lysine providing acidic and basic side chains. The peptide emerged from extracellular-matrix-oriented peptide research and has been described in the context of screening short sequences for fibroblast responses. Its ingredient name should not be taken to imply terminal modification: free termini, salt form and any additional chemical modifications need to be checked in the batch specification.
Laboratory investigations focus on extracellular-matrix expression rather than an established receptor-binding mechanism. Cultured dermal fibroblasts allow measurements of collagen-related transcripts, secreted procollagen and fibronectin, although these endpoints describe different stages of matrix production. Increased transcript abundance does not necessarily mean increased deposition of organised matrix. For research-only comparisons, cell number, culture duration and matrix turnover should be measured alongside expression endpoints, with appropriate controls for assay interference and general changes in cell viability.
Laboratory notes
- Confirm GEKG sequence identity, terminal chemistry and counterion before comparing materials from different sources.
- Normalise secreted matrix-marker measurements to viable cell number or another justified measure of cellular biomass.
- Measure medium background and distinguish soluble procollagen from deposited collagen when selecting analytical endpoints.
Storage and reconstitution basics: storage guide.
Questions about Tetrapeptide-21
What is the sequence of Tetrapeptide-21?
It is commonly specified as Gly-Glu-Lys-Gly, or GEKG. The supplier's analytical documentation should confirm sequence and terminal chemistry.
Does Tetrapeptide-21 have a defined receptor target?
A specific directly bound receptor has not been established. Its laboratory characterisation centres on fibroblast and extracellular-matrix-associated responses.
Are collagen transcripts and deposited collagen interchangeable endpoints?
No. Transcripts reflect gene expression, whereas deposited collagen also depends on translation, secretion, processing, assembly and degradation.
Is Tetrapeptide-21 for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.