PSMα4 peptide

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

PSMα peptides, produced by Staphylococcus aureus, are a group of hydrophobic peptides, often formylated at the N-terminal, ranging from 20-25 amino acids in length. These peptides play a role in the bacterium's virulence, acting as chemoattractants for neutrophils at high nanomolar concentrations and causing cytolysis at micromolar concentrations. They are also involved in promoting phagosome lysis and bacterial escape, as well as in the rapid induction of neutrophil extracellular trap (NET) formation​

The PSMα peptides differentially modulate the aggregation of α-synuclein (α-syn), a protein associated with Parkinson's disease. PSMα1 and PSMα4 are described to form fibrillar amyloid structures on their own, while PSMα2 and PSMα3 form α-helix-rich amorphous aggregates.

• Chu, M., Zhang, Mb., Liu, Yc. et al. Role of Berberine in the Treatment of Methicillin-Resistant Staphylococcus aureus Infections. Sci Rep 6, 24748 (2016).

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.