Endothelin-2 (49-69 aa, human) peptide

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

Batch to batch variation of the purity

Endothelin-2 (ET-2) is a 21-amino acid vasoactive peptide that belongs to the endothelin family, which also includes ET-1 and ET-3. These peptides are produced by various cell types and bind to two G-protein-coupled transmembrane receptors, the ET-A receptor (ET-RA) and the ET-B receptor (ET-RB). ET-2 is encoded by a distinct, independently expressed gene and has been shown to be expressed in several human tumors, including breast carcinomas. In infiltrating ductal carcinomas of the breast, ET-2 and ET-RB mRNA are frequently detected, whereas they are largely absent in normal breast tissue. ET-2 expression is regulated by hypoxia in a hypoxia-inducible factor 1 (HIF-1)-dependent manner, with mRNA levels increasing within hours of hypoxic exposure in breast tumor cell lines.

In hypoxic conditions, ET-2 acts as an autocrine survival factor for breast tumor cells. The peptide is released by tumor cells and signals primarily through the ET-RB receptor to protect cells from hypoxia-induced apoptosis. This protective effect is specific to hypoxic stress, as ET-2 or its receptor antagonists have no significant effect on cell growth or survival under normoxic conditions. The upregulation of ET-2 and its receptors during hypoxia represents a cellular mechanism that allows tumor cells to withstand low-oxygen environments, and this process is colocalized with hypoxic regions within tumors.

• Grimshaw MJ, Naylor S, Balkwill FR. Endothelin-2 is a hypoxia-induced autocrine survival factor for breast tumor cells. Mol Cancer Ther. 2002 Dec;1(14):1273-81. PMID: 12516960.

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.