Lactoferricin B peptide

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

Batch to batch variation of the purity

Bovine lactoferricin (LfcinB) is a cationic antimicrobial peptide derived from the N-terminus of bovine lactoferrin, an iron-binding glycoprotein found in neutrophil granules and secretions such as tears, saliva, and milk. LfcinB consists of amino acid residues 17–41 and possesses a net charge of +8 due to five arginine and three lysine residues, along with two tryptophan and two phenylalanine residues that confer both aromatic and hydrophobic properties. The peptide adopts an amphipathic beta-sheet configuration in aqueous solution, with hydrophobic residues aligned on one face and basic residues on the opposing face, enabling interaction with anionic components of cell membranes. The antimicrobial core of LfcinB, designated LfcinB6, comprises the six-amino acid sequence RRWQWR. This core peptide adopts a well-defined amphipathic structure when bound to sodium dodecyl sulfate micelles.

LfcinB6 has a net charge of +3 conferred by its three arginine residues. Unlike the full-length LfcinB, LfcinB6 does not bind to or disrupt the cell membranes of cancer cells, such as T-leukemia or breast carcinoma cells, and shows weaker binding to isolated mitochondria. However, when delivered directly into the cytosolic compartment via fusogenic liposomes, LfcinB6 exhibits strong cytotoxicity. This intracellular cytotoxicity involves cathepsin B and caspase activation, but not reactive oxygen species, and does not involve mitochondrial membrane permeabilization or cytochrome c release, indicating a mechanism of action distinct from that of the full-length LfcinB peptide.

• Goodman RE, Schanbacher FL. Bovine lactoferrin mRNA: sequence, analysis, and expression in the mammary gland. Biochem Biophys Res Commun. 1991 Oct 15;180(1):75-84. doi: 10.1016/s0006-291x(05)81257-4. PMID: 1718281.
• Richardson A, de Antueno R, Duncan R, Hoskin DW. Intracellular delivery of bovine lactoferricin's antimicrobial core (RRWQWR) kills T-leukemia cells. Biochem Biophys Res Commun. 2009 Oct 30;388(4):736-41. doi: 10.1016/j.bbrc.2009.08.083. Epub 2009 Aug 21. PMID: 19699713.

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.