Bactericidal action of peptide antibiotic AS-48 against <i>Escherichia coli</i> K-12

Gálvez, Antonio; Valdivia, Eva; Martínez, M.; Maqueda, Mercedes

doi:10.1139/m89-048

Cited by 31 publications

(28 citation statements)

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“…Although the inhibitory spectrum of bacteriocins from LAB is often restricted to Gram-positive bacteria, several reports have described strong inhibition of Gram-negatives, including E. coli and/or Salmonella (Ben Omar et al, 2006;Caridi, 2002;Gálvez, Valdivia, Martínez, & Maqueda, 1989;Lash, Mysliwiec, & Gouram, 2005;Lewus, Kaiser, & Montville, 1991;Messi, Bondi, Sabia, Battini, & Manicardi, 2001;Ogunbanwo, Sanni, & Onilude, 2003;Rubia-Soria et al, 2006;Todorov & Dicks, 2004. Results from the present study indicate that inhibition of target bacteria greatly depended on incubation temperature, with best results at 22 and 30°C.…”

Section: Discussionsupporting

confidence: 46%

Inhibition of food poisoning and pathogenic bacteria by Lactobacillus plantarum strain 2.9 isolated from ben saalga, both in a culture medium and in food

et al. 2008

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Section: Discussionsupporting

confidence: 46%

Inhibition of food poisoning and pathogenic bacteria by Lactobacillus plantarum strain 2.9 isolated from ben saalga, both in a culture medium and in food

et al. 2008

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“…Thus, the removal of the cell envelopes did not diminish the sensitivity of E. faecalis cells. E. coli vesicles were more sensitive to AS-48 at 4 pg/ml than were intact cells, in which the effects of AS-48 were observed at concentrations 10 to 15 times higher (7).…”

Section: Methodsmentioning

confidence: 90%

Permeation of bacterial cells, permeation of cytoplasmic and artificial membrane vesicles, and channel formation on lipid bilayers by peptide antibiotic AS-48

et al. 1991

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Peptide AS-48 induces ion permeation, which is accompanied by the collapse of the cytoplasmic membrane potential, in sensitive bacteria. Active transport by cytoplasmic membrane vesicles is also impaired by AS-48. At low concentrations, this peptide also causes permeability of liposomes to low-molecular-weight compounds without a requirement for a membrane potential. Higher antibiotic concentrations induce severe disorganization, which is visualized under electron microscopy as aggregation and formation of multilamellar structures. Electrical measurements suggest that AS-48 can form channels in lipid bilayers.The production of bacteriocins and other antibacterial substances by group D enterococci is well documented (2, 5, 11, 17), although broad-spectrum inhibitors are rarely found. In addition, the mode of action of most of the antibacterial substances in this group has not been studied extensively. An enterococcal strain isolated in our laboratory (Enterococcus faecalis subsp. liquefaciens S-48) produces two inhibitory substances: bacteriocin Bc-48, which has a molecular mass of 77 kDa and is described elsewhere (14a), and antibiotic AS-48. This peptide has been purified from culture supernatants of strain S-48 and its nonbacteriocinogenic mutant A-48-32. Reversed-phase liquid chromatography analysis revealed a single peptide with a molecular mass of 7.4 kDa, as estimated from its amino acid composition (4). AS-48 is rich in basic and neutral amino acids and has an isoelectric point close to 10.5. It resembles other antimicrobial peptides, such as nisin (8), , and the small bacteriocin C3603 (9). AS-48 is encoded by the 56-kb conjugative plasmid pMB2, which was transferred to plasmid-free E. faecalis OG1X. This plasmid carries the genes for immunity and for the production of AS-48 (15).Peptide AS-48 has a broad inhibitory spectrum against gram-positive and gram-negative bacteria. Its bactericidal effect is mediated through the inhibition of amino acid uptake, 02 consumption, and the alteration of the cytoplasmic content of K+ and Na+ ions (6). AS-48 also induces bacteriolysis in several gram-positive bacteria after prolonged incubation, an effect that is considered to be secondary. This paper describes the effects of AS-48 on the permeability of whole cells and cytoplasmic membrane vesicles derived from sensitive bacteria. Its action on artificial membranes (liposomes) is also discussed with regard to changes in permeability and morphological alterations observed under electron microscopy. The formation of channels in lipid bilayers is also suggested. MATERIALS AND METHODSBacterial strains and growth media. E. faecalis S-47 was isolated in our laboratory and described elsewhere (5). Other bacteria used were purchased from culture collections or * Corresponding author. belonged to our laboratory collection. E. faecalis S-47 was grown in brain heart infusion broth (Becton Dickinson and Co., Paramus, N.J.). Other bacterial strains were grown in Luria broth at 37°C under agitation.Chemicals. All radioactive materi...

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“…We have been working in recent years on one of these peptides, the bacteriocin AS-48, a 70-residue cyclic peptide produced by Enterococcus faecalis S-48, which shows a broad antimicrobial spectrum against both Gram-positive and Gramnegative bacteria (1)(2)(3). Bacteriocin AS-48 is encoded by the 68-kb pheromone-responsive plasmid pMB2 (4), and the gene cluster involved in production and immunity has been identified (5).…”

mentioning

confidence: 99%

“…Bacteriocin AS-48 is encoded by the 68-kb pheromone-responsive plasmid pMB2 (4), and the gene cluster involved in production and immunity has been identified (5). This peptide exerts a bactericidal action on sensitive cells (2), and its target is the cytoplasmic membrane, in which it opens pores, leading to the dissipation of the protonmotive force and cell death (6), a mechanism similar to that proposed for the action of defensins or, most generally, cationic antibacterial peptides (7).…”

mentioning

confidence: 99%

Bacteriocin AS-48, a microbial cyclic polypeptide structurally and functionally related to mammalian NK-lysin

González

Langdon

Bruix

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

160

141

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The solution structure of bacteriocin AS-48, a 70-residue cyclic polypeptide from Enterococcus faecalis, consists of a globular arrangement of five ␣-helices enclosing a compact hydrophobic core. The head-to-tail union lies in the middle of helix 5, a fact that is shown to have a pronounced effect on the stability of the three-dimensional structure. Positive charges in the side chains of residues in helix 4 and in the turn linking helix 4 to helix 5 form a cluster that most probably determine its antibacterial activity by promoting pore formation in cell membranes. A similar five-helix structural motif has been found in the antimicrobial NK-lysin, an effector polypeptide of T and natural killer (NK) cells. Bacteriocin AS-48 lacks the three disulfide bridges characteristic of the saposin fold present in NK-lysin, and has no sequence homology with it. Nevertheless, the similar molecular architecture and high positive charge strongly suggest a common mechanism of antibacterial action.cationic antibacterial peptides ͉ NMR solution structure ͉ five-helix globule ͉ cyclic polypeptide ͉ membrane permeation

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Bactericidal action of peptide antibiotic AS-48 against Escherichia coli K-12

Cited by 31 publications

References 3 publications

Inhibition of food poisoning and pathogenic bacteria by Lactobacillus plantarum strain 2.9 isolated from ben saalga, both in a culture medium and in food

Inhibition of food poisoning and pathogenic bacteria by Lactobacillus plantarum strain 2.9 isolated from ben saalga, both in a culture medium and in food

Permeation of bacterial cells, permeation of cytoplasmic and artificial membrane vesicles, and channel formation on lipid bilayers by peptide antibiotic AS-48

Bacteriocin AS-48, a microbial cyclic polypeptide structurally and functionally related to mammalian NK-lysin

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