Antibacterial Activity of Synthetic Peptides Derived from Lactoferricin againstEscherichia coliATCC 25922 andEnterococcus faecalisATCC 29212

Abstract

Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i) the incorporation of unnatural amino acids in the sequence, the (ii) reduction or (iii) elongation of the peptide chain length, and (iv) synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR) and I.4 ((RRWQWR)4K2 Ahx 2C2) exhibit bigger or similar activity against E. coli (MIC 4–33 μM) and E. faecalis (MIC 10–33 μM) when they were compared with lactoferricin protein (LF) and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA) and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE). It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

A PiggyBac mediated approach for lactoferricin gene transfer in bovine mammary epithelial stem cells for management of bovine mastitis

“…Transgenesis has been suggested as a means to combat mastitis [ 28 ]. Recent studies have been used lactoferricin as anti-bacterial agent against diarrheal organisms ( S. aureus and E. coli ) [ 29 , 30 ].…”

“…Bi et al [ 38 ], demonstrated the bovine lactoferricin antimicrobial activity assayed by agar diffusion test only. Lactoferricin was shown to interact with lipopolysaccharide (LPS) of the Gram-negative bacterial membrane of E. coli [ 39 ] hence it has high antibacterial activity against E. coli [ 40 ]. Our findings also showed the comparatively higher antibacterial property of bovine lactoferricin against E. coli in comparison to S. aureus .…”

Design, Synthesis and Evaluation of Branched RRWQWR-Based Peptides as Antibacterial Agents Against Clinically Relevant Gram-Positive and Gram-Negative Pathogens

“…We designed and synthesized three new cationic peptides based on the RRWQWR motif and prepared two other peptides for comparison (hy): LfcinB (20–25) (RRWQWR) and LfcinB (17–31) (FKCRRWQWRMKKLGA), the latter as reference peptide or antibacterial activity, based on results previously reported by Leon-Calvijo et al ( 2015 ). All peptides were synthesized on solid phase using the Fmoc/tBu methodology, as previously reported (Solarte et al, 2015 ; Huertas et al, 2017 ).…”

“…To obtain the dimeric peptide, di-FMOC-protected lysine was used, which enabled simultaneous synthesis of the two peptide chains (one from the α-amino group and the other, from the ε-amino group of this amino acid). The tetrameric peptide was obtained via oxidation of the dimeric peptide, (RRWQWR) 2 -K-Ahx-C, with 10% DMSO % in PBS buffer (pH 7.5), as described by Leon-Calvijo et al ( 2015 ), which led to formation of a disulfide bond between the side chains of the cysteine residues at the carboxyl terminus (Figure 1 ). All peptides were >90% pure (as determined by RP-HPLC) and had the expected molecular weight (determined by MALDI-TOF MS).…”

“…AMPs with reported antimicrobial activity include peptides derived from the protein bovine lactoferricin B (LfcinB) (Leon-Calvijo et al, 2015 ). Interestingly, this activity has been attributed to the RRWQWR motif within LfcinB, which is considered to be the smallest known motif with antibacterial (Richardson et al, 2009 ; Leon-Calvijo et al, 2015 ; Huertas et al, 2017 ) or anticarcinogenic (Solarte et al, 2015 ) activity.…”