DR8 peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

DR8 (DHNNPQIR-NH2) is an antioxidant peptide extracted and purified from rapeseed (Brassica campestris L.). It belongs to a class of naturally occurring peptides with biological activity. However, natural peptides are susceptible to degradation by proteases, which limits their stability and duration of action.

To address this limitation, a structural analog, DR7dA [DHNNPQ(D-alanine)R-NH2], was developed by replacing L-isoleucine with D-alanine. This modification significantly improved the serum stability of DR7dA compared to its parent peptide, DR8. DR7dA retains the ability to inhibit fibrogenesis and extracellular matrix deposition by suppressing the mitogen-activated protein kinase (MAPK) signaling pathway and reducing oxidative stress. These properties make it a promising candidate for further scientific investigation.

• [1] Cheng L, Wang D, Deng B, Li J, Zhang J, Guo X, Yan T, Yue X, An Y, Zhang B, Xie J. DR7dA, a Novel Antioxidant Peptide Analog, Demonstrates Antifibrotic Activity in Pulmonary Fibrosis In Vivo and In Vitro. J Pharmacol Exp Ther. 2022 Aug;382(2):100-112. doi: 10.1124/jpet.121.001031. Epub 2022 Jun 30. PMID: 35772783.
• [2] Xu F, Wang L, Ju X, et al. Transepithelial Transport of YWDHNNPQIR and Its Metabolic Fate with Cytoprotection against Oxidative Stress in Human Intestinal Caco-2 Cells. Journal of Agricultural and Food Chemistry. 2017;65(10):2056-2065 DOI: 10.1021/acs.jafc.6b04731
• [3] Wang D, Yan Z, Bu L, et al. Protective effect of peptide DR8 on bleomycin-induced pulmonary fibrosis by regulating the TGF-β/MAPK signaling pathway and oxidative stress. Toxicology and Applied Pharmacology. 2019;382:114703 DOI: 10.1016/j.taap.2019.114703
• [4] Deng B, Yang W, Wang D, et al. Peptide DR8 suppresses epithelial-to-mesenchymal transition via the TGF-β/MAPK signaling pathway in renal fibrosis. Life Sciences. 2020;261:118465 DOI: 10.1016/j.lfs.2020.118465

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.