11R-VIVIT peptide

• COA/MS/HPLC Report
• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

You may also need the inactive scrambled control peptide:11R-VEET peptide

The 11R-VIVIT peptide is a synthetic cell-penetrating construct designed to interfere with the interaction between the calcium-dependent phosphatase calcineurin and the nuclear factor of activated T cells (NFAT) transcription factors. It consists of an 11-arginine (11R) transduction domain linked via a three-glycine spacer to the high-affinity VIVIT sequence (MAGPHPVIVITGPHEE), which mimics the PxIxIT motif found in NFAT proteins. This motif serves as the major docking site for calcineurin on NFAT, and the VIVIT sequence was optimized through affinity-driven selection from combinatorial peptide libraries to bind calcineurin with greater strength than the native NFATc2 motif (PRIEIT). The 11R sequence facilitates translocation across cellular membranes, enabling the peptide to target intracellular signaling pathways.

In glioma cells, which predominantly express NFATc3, 11R-VIVIT unexpectedly activates NFAT signaling rather than inhibiting it. This is evidenced by increased NFAT-dependent promoter activity, upregulated expression of endogenous NFAT-target genes such as COX2 and c-MYC, and translocation of NFAT proteins from the cytoplasm to the nucleus. This aberrant activation may stem from the presence of two calcineurin docking sites in NFATc3 (a PxIxIT motif and an additional LxVP motif), allowing calcineurin to still interact with NFAT through the LxVP site while the PxIxIT site is blocked by the VIVIT peptide. The spherical structure of a GFP tag in VIVIT-GFP fusion proteins may sterically hinder access to both docking sites, explaining why that construct inhibits NFAT signaling, whereas the linear 11R-VIVIT does not.

• Zhang L, Li R, Shi W, Liang X, Liu S, Ye Z, Yu C, Chen Y, Zhang B, Wang W, Lai Y, Ma J, Li Z, Tan X. NFAT2 inhibitor ameliorates diabetic nephropathy and podocyte injury in db/db mice. Br J Pharmacol. 2013 Sep;170(2):426-39. doi: 10.1111/bph.12292. PMID: 23826864; PMCID: PMC3834765.
• Ellert-Miklaszewska A, Szymczyk A, Poleszak K, Kaminska B. Delivery of the VIVIT Peptide to Human Glioma Cells to Interfere with Calcineurin-NFAT Signaling. Molecules. 2021 Aug 7;26(16):4785. doi: 10.3390/molecules26164785. PMID: 34443374; PMCID: PMC8400789.

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.