Testagen

Testagen is the synthetic tetrapeptide Lys-Glu-Asp-Gly (KEDG). In the indexed literature, KEDG was synthesized from the amino acid composition of anterior pituitary peptide complexes and tested in hypophysectomized chickens, where thyroid and thymus structure were examined. Other Testagen peptide papers are molecular: uptake into HeLa cell nuclei, binding to DNA and histones, and a 2025 materials study of its adsorption on copper. Research Market supplies Testagen as a lyophilized research reagent, with purity and identity data for each lot reported on its certificate of analysis. It is sold strictly for laboratory research use.

Chemical structure and identification

• Amino acid sequence: Lys-Glu-Asp-Gly (KEDG)
• Synonyms: H-Lys-Glu-Asp-Gly-OH
• Form: Lyophilized powder
• Analytical methods: RP-HPLC for purity and mass spectrometry for identity, reported on the batch certificate of analysis

Research applications

• Nuclear uptake: FITC-labeled testagen entered the cytoplasm, nucleus and nucleolus of HeLa cells and bound preferentially to CAG-containing deoxyribooligonucleotides in vitro [1]
• Histone binding: Fluorescence quenching showed Lys-Glu-Asp-Gly binding FITC-labeled wheat histones H1, H2B, H3 and H4, an interaction the authors linked to epigenetic regulation [2]
• Thyroid function in hypophysectomized chickens: Forty days of Lys-Glu-Asp-Gly in neonatally hypophysectomized chickens increased thyrotropic and thyroid hormone concentrations and restored thyroid structure [3]
• Thymus morphology: In hypophysectomized young and old birds, Lys-Glu-Asp-Gly promoted recovery of thymic structure more than the posterior pituitary peptide Ala-Glu-Asp-Gly [4]
• Surface adsorption: On copper in sodium chloride solution, H-Lys-Glu-Asp-Gly-OH reached about 86% corrosion inhibition efficiency, with adsorption fitting the Freundlich isotherm [5]

Reference citations

1. Fedoreyeva L. et al. (2011). Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA. Biochemistry (Mosc), 76(11):1210–1219. PMID 22117547 · DOI
2. Fedoreyeva L. et al. (2013). Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides. Biochemistry (Mosc), 78(2):166–175. PMID 23581987 · DOI
3. Kuznik B. et al. (2008). Effect of tetrapeptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the structure and function of the thyroid gland in neonatally hypophysectomized chickens. Bull Exp Biol Med, 145(1):104–107. PMID 19024016 · DOI
4. Pateyk A. et al. (2013). Effect of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the morphology of the thymus in hypophysectomized young and old birds. Bull Exp Biol Med, 154(5):681–685. PMID 23658898 · DOI
5. Dobriţescu A. et al. (2025). The Inhibitory Effect and Adsorption Properties of Testagen Peptide on Copper Surfaces in Saline Environments: An Experimental and Computational Study. Molecules, 30(15):3141. PMID 40807317 · DOI

Literature summaries describe published preclinical research and are not claims about this product’s effects in humans or animals.