Inducing pheromone 673/IP-673 peptide

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

Batch to batch variation of the purity

The inducing factor (IF) from Lactobacillus sake LTH673 is a 19-amino acid peptide with a basic character and a calculated pI of 11.8. Structurally, IF can form a highly amphiphilic alpha-helix, as demonstrated by circular dichroism studies, which revealed helical conformation in membrane-mimicking environments such as trifluoroethanol, SDS, and dodecylphosphocholine micelles. Despite its structural similarities to bacteriocins, IF lacks significant antimicrobial activity, requiring concentrations 30 to 200 µg/mL to inhibit growth of tested bacterial strains, compared to the typical bacteriocin range of 1–100 ng/mL.

IF functions as a signaling molecule in an autoinduction pathway, triggering the expression of genes involved in the production of sakacin P, a bacteriocin, as well as its own synthesis. Induction occurs at minimal IF concentrations of 0.2 ng/mL (~0.1 nM) and is an all-or-nothing process. The peptide is secreted by L. sake and accumulates in the culture medium, suggesting a role in cell-density-dependent regulation. Transcription of the sakP gene, encoding sakacin P, is rapidly activated within 30 minutes of IF addition, leading to subsequent peptide production.

• Eijsink VG, Brurberg MB, Middelhoven PH, Nes IF. Induction of bacteriocin production in Lactobacillus sake by a secreted peptide. J Bacteriol. 1996;178(8):2232-7.

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.