Parstatin(mouse) peptide

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

Batch to batch variation of the purity

Parstatin(mouse) is a 41-amino acid peptide cleaved from the N-terminal extracellular domain of protease-activated receptor 1 (PAR1) upon thrombin activation. This hydrophobic peptide exhibits cell-penetrating properties, enabling intracellular activity. Parstatin(mouse) shares 78% sequence identity with human parstatin in its N-terminal hydrophobic domain, which is critical for its biological function.

Studies demonstrate parstatin(mouse) modulates endothelial cell behavior by inhibiting extracellular signal-regulated kinase (ERK) phosphorylation, inducing cell cycle arrest and promoting caspase-dependent apoptosis. While exhibiting similar mechanisms to human parstatin, the mouse variant shows reduced potency in angiogenesis inhibition assays, suggesting species-specific functional differences. The peptide's hydrophobic region facilitates membrane interaction and cellular uptake, while its hydrophilic C-terminal domain appears less conserved across species.

• Zania P, Gourni D, Aplin AC, Nicosia RF, Flordellis CS, Maragoudakis ME, Tsopanoglou NE. Parstatin, the cleaved peptide on proteinase-activated receptor 1 activation, is a potent inhibitor of angiogenesis. J Pharmacol Exp Ther. 2009 Feb;328(2):378-89. doi: 10.1124/jpet.108.145664. Epub 2008 Nov 6. PMID: 18988770.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.