Antibacterial spectrum of lactoferricin B, a potent bactericidal peptide derived from the N‐terminal region of bovine lactoferrin

Abstract

A physiologically diverse range of Gram-positive and Gram-negative bacteria was found to be susceptible to inhibition and inactivation by lactoferricin B, a peptide produced by gastric pepsin digestion of bovine lactoferrin. The list of susceptible organisms includes Escherichia coli, Salmonella enteritidis, Klebsiella pneumoniae, Proteus vulgaris, Yersinia enterocolitica, Pseudomonas aeruginosa, Campylobacter jejuni, Staphylococcus aureus, Streptococcus mutans, Corynebacterium diphtheriae, Listeria monocytogenes and Clostridium perfringens. Concentrations of lactoferricin B required to cause complete inhibition of growth varied within the range of 0.3 to 150 micrograms/ml, depending on the strain and the culture medium used. The peptide showed activity against E. coli O111 over the range of pH 5.5 to 7.5 and was most effective under slightly alkaline conditions. Its antibacterial effectiveness was reduced in the presence of Na+, K+, Mg2+ or Ca2+ ions, or in the presence of various buffer salts. Lactoferricin B was lethal, causing a rapid loss of colony-forming capability in most of the species tested. Pseudomonas fluorescens, Enterococcus faecalis and Bifidobacterium bifidum strains were highly resistant to this peptide.

Length Effects in Antimicrobial Peptides of the (RW)nSeries

“…The HI, defined as the ratio of HD 50 to IC 50 , indicates the selectivity of (RW) n -NH 2 peptides (E. coli, black bars; S. aureus, gray bars). 2 and therefore a similar extent of Trp side-chain burial. However, increased protection in the presence of POPG vesicles is observed for longer (RW) n (n, Ն3) peptides, while the Trp residues of these peptides appear to be less accessible in POPG than in POPC (Table 3).…”

“…The apparent conformational changes are a function of chain length and lipid composition. For example, while RW and (RW) 2 have similar spectra and may be unfolded in the presence of water or lipids, the CD of (RW) 3 and that of (RW) 4 show differences in the presence of POPG but not in the presence of POPC (Fig. 2).…”

“…Lactoferricin B, indolicidin, and tritrpticin (2,38,40) are natural AMPs with sequences longer than 12 amino acids. PW2 and hexamers of the Ac-RRWWXX-NH 2 sequence are active antibacterial peptides containing 6 to 12 amino acids derived from screening phage displays and synthetic combinatorial libraries, respectively (3,52).…”

Antibacterial Properties of hLf1–11 Peptide onto Titanium Surfaces: A Comparison Study Between Silanization and Surface Initiated Polymerization

“…In a previous study, we introduced the 1-11 antimicrobial sequence of the human lactoferrin protein (hLf), the hLf1-11 peptide, as a potent AMP with capacity to reduce bacterial adhesion on titanium implants 8 . Lactoferrin and Lf-derived peptides have been shown to inhibit viral 14 , fungal 15 , parasitic and bacterial infections [16][17][18] . The antibacterial activity of lactoferrin has been widely documented both in vitro and in vivo for Gram-positive and Gram-negative bacteria 19 .…”

Bovine Lactoferricin Inhibits Basic Fibroblast Growth Factor- and Vascular Endothelial Growth Factor165-Induced Angiogenesis by Competing for Heparin-Like Binding Sites on Endothelial Cells

“…19 Bovine lactoferricin (LfcinB) is a 25-amino acid cationic peptide with an amphipathic, anti-parallel ␤-sheet structure that is obtained by acidpepsin hydrolysis of the N-terminal region of lactoferrin from cow's milk. 20 LfcinB accounts for the iron-independent, anti-microbial action of bovine lactoferrin because the peptide is cytotoxic for a diverse range of gram-positive and gram-negative bacteria, 21 as well as showing anti-viral 22 and anti-fungal activity. 23 There is evidence that LfcinB also possesses potent in vitro and in vivo anti-cancer activity, 24,25 which is likely related to the ability of LfcinB to disrupt the plasma membrane of neoplastic cells.…”