A3-APO peptide

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

Batch to batch variation of the purity

The A3-APO peptide is a synthetic proline-rich dimeric antibacterial peptide designed to target bacteria through a dual mode of action. It features distinct domains for interaction with both bacterial membranes and intracellular targets, specifically the 70-kDa heat shock protein DnaK. The peptide's structure includes conserved residues critical for DnaK binding (Asp4-Lys5 and Tyr9-Leu-Pro-Arg-Pro13) and membrane penetration (arginine-proline-rich regions). A3-APO exhibits enhanced stability against proteolytic degradation and demonstrates selective activity against Gram-negative bacteria, particularly Enterobacteriaceae, by disrupting membrane integrity and inhibiting chaperone-assisted protein folding.

Notably, A3-APO binds to the C-terminal helical lid of bacterial DnaK, impairing its function without affecting mammalian Hsp70. Its dimeric architecture contributes to improved membrane penetration and reduced susceptibility to resistance induction compared to monomeric analogs. The peptide's sequence optimizes functional motifs from native proline-rich peptides, such as pyrrhocoricin and drosocin, while eliminating non-essential elements. This design results in potent antibacterial effects, particularly against strains with complementary DnaK sequences, while maintaining low eukaryotic toxicity.

• Rozgonyi F, Szabo D, Kocsis B, Ostorházi E, Abbadessa G, Cassone M, Wade JD, Otvos L Jr. The antibacterial effect of a proline-rich antibacterial peptide A3-APO. Curr Med Chem. 2009;16(30):3996-4002. doi: 10.2174/092986709789352295. PMID: 19747127.
• Szabo D, Ostorhazi E, Binas A, Rozgonyi F, Kocsis B, Cassone M, Wade JD, Nolte O, Otvos L Jr. The designer proline-rich antibacterial peptide A3-APO is effective against systemic Escherichia coli infections in different mouse models. Int J Antimicrob Agents. 2010 Apr;35(4):357-61. doi: 10.1016/j.ijantimicag.2009.10.015. Epub 2009 Dec 23. PMID: 20031377.

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.