Influenza HA (307-319) peptide

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

Batch to batch variation of the purity

The Influenza HA (307-319) peptide corresponds to a region within the hemagglutinin (HA) glycoprotein of influenza A virus. Hemagglutinin is a surface protein that facilitates viral entry into host cells by binding to sialic acid receptors on the cell surface. The HA protein is synthesized as a precursor (HA0) and is cleaved by host proteases into two subunits, HA1 and HA2. This cleavage exposes the fusion peptide at the N-terminus of HA2, which is essential for membrane fusion during viral entry. The specific region from residues 307 to 319 is part of the cleavage site, which contains a single arginine residue critical for proteolytic activation. The amino acid sequence and properties of this cleavage site influence the virus's ability to infect cells and its tissue tropism.

Structural studies of HA reveal that the cleavage site is located near the base of the globular head domain. The sequence around this site, including residues 307-319, is highly conserved among influenza strains, but variations can affect protease susceptibility and viral pathogenicity. For instance, the presence of multiple basic amino acids at the cleavage site in some avian influenza viruses allows cleavage by ubiquitous proteases, leading to systemic infection. In contrast, human influenza viruses typically have a single basic residue at this site, restricting cleavage to specific tissues. The HA (307-319) peptide thus represents a key functional region involved in the proteolytic activation of HA, which is a prerequisite for membrane fusion and viral infectivity.

• Sriwilaijaroen N, Suzuki Y. Molecular basis of the structure and function of H1 hemagglutinin of influenza virus. Proc Jpn Acad Ser B Phys Biol Sci. 2012;88(6):226-49. doi: 10.2183/pjab.88.226. PMID: 22728439; PMCID: PMC3410141.

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.