RETF-4NA peptide

RETF-4NA peptide

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

Batch to batch variation of the purity

Ac-RETF-pNA

Ac-Arg-Glu-Thr-Phe-pNA

4

95.44%

C₃₂H₄₃N₉O₁₀

713.73

Synthetic

Powder

RETF-4NA (acetyl-L-Arg-Glu-Thr-Phe-4-nitroanilide) is a custom-synthesized peptide substrate designed for the assay of chymase activity. It was developed based on the results of combinatorial screening of tetrapeptide substrates with recombinant human chymase. The kinetic performance of RETF-4NA was compared with other peptide-based colorimetric substrates, such as AAPF-4NA, AEPF-4NA, and VPF-4NA, using recombinant human chymase, human cathepsin G, and bovine chymotrypsin. RETF-4NA was found to be substantially more selective for chymase compared to cathepsin G and chymotrypsin, and it yielded similar specificity constants to VPF-4NA for chymase. In serum-based assays, RETF-4NA showed low background hydrolysis and high selectivity for chymase. It was able to detect active chymase in serum at or above ~1 pM and had a wide dynamic range. Additionally, chymase activity measured with RETF-4NA in spiked serum was stable, and the substrate hydrolysis by α₂M-bound chymase was more efficient than that by free chymase. Overall, RETF-4NA is a sensitive and selective substrate for chymase, which is important for the development of a serum assay to detect chymase activity, especially in the context of studying mast cell-related diseases like mastocytosis.

Normally, this peptide will be delivered in lyophilized form and should be stored in a freezer at or below -20 °C. For more details, please refer to the manual: Handling and Storage of Synthetic Peptides

• Raymond WW, Su S, Makarova A, Wilson TM, Carter MC, Metcalfe DD, Caughey GH. Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity. J Immunol. 2009 May 1;182(9):5770-7. doi: 10.4049/jimmunol.0900127. PMID: 19380825; PMCID: PMC2756746.

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.