Walking the fine line between intracellular and membrane activities of antibacterial peptides

Bower, Molly A.; Čudić, Mare; Campbell, William; Wade, John D.; Ötvös, László

doi:10.1007/bf02442578

Cited by 8 publications

(11 citation statements)

References 40 publications

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“…From the point of view of antibacterial activity, the lack of mammalian toxicity is due to the inhibition of a bacteria-specific intracellular protein rather than to activity at bacterial membranes. Magainin 2 is less active against E. coli than the Pip-pyrr-MeArg dimer but exhibits remarkably increased toxicity to mammalian cells …”

Section: Discussionmentioning

confidence: 99%

An Insect Antibacterial Peptide-Based Drug Delivery System

et al. 2004

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The ability of the short, proline-rich native antibacterial peptides to penetrate bacterial and host cells suggests the utility of these transport systems in delivering peptidic cargo into cells. We studied the uptake of pyrrhocoricin and its most potent dimeric analogue by bacteria as well as human dendritic cells and fibroblasts. Native pyrrhocoricin entered the susceptible organism Escherichia coli very efficiently and the nonsusceptible bacterium Staphylococcus aureus to a significant degree. The antibacterial peptide also penetrated human monocyte-derived dendritic cells. It failed, however, to enter fibroblasts, whereas the designer analogue Pip-pyrr-MeArg dimer penetrated all the cell types that were studied. When glucoincretin hormone Glp-1 fragment 7-36 was cosynthesized with the dimer, the antibacterial peptide derivative lost its ability to cross the bacterial membrane layer. In contrast, a chimera of the Pip-pyrr-MeArg dimer and two copies of a shorter (nine residues) class I major histocompatibility complex epitope successfully entered bacterial and mammalian cells. While the Pip-pyrr-MeArg dimer was not immunogenic when inoculated into mice, the chimera elicited a strong cytotoxic T-cell response, indicating the maintenance of the antigenic integrity of the cargo in the peptide conjugate. The chimera when tested for its immunological properties activated human dendritic cells significantly more strongly than any of the two independent fragments alone, yet lacked mammalian cell toxicity. These results confirm the utility of designed pyrrhocoricin analogues for delivery of peptidic cargo across cell membranes in general, and their potential as carriers for epitope-based vaccines in particular.

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Section: Discussionmentioning

confidence: 99%

An Insect Antibacterial Peptide-Based Drug Delivery System

et al. 2004

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“…Otvos et al also demonstrated that slight changes in amino acid composition of the nonlytic PR-AMP pyrrhocoricin resulted in derivatives with an altered mode of action. It was shown that the dimeric pyrrhocoricin derivative Pip-pyrr-MeArg (39) and also the mixed pyrrhocoricin-drosocin dimer (40) kill bacteria better than the native proline-rich peptide due to improved activity on bacterial membranes (39).…”

Section: Mode Of Action Of Bac7(1-35) Against P Aeruginosamentioning

confidence: 99%

The Mechanism of Killing by the Proline-Rich Peptide Bac7(1–35) against Clinical Strains of Pseudomonas aeruginosa Differs from That against Other Gram-Negative Bacteria

Runti

Benincasa

Giuffrida

et al. 2017

Antimicrob Agents Chemother

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Pseudomonas aeruginosa infections represent a serious threat to worldwide health. Proline-rich antimicrobial peptides (PR-AMPs), a particular group of peptide antibiotics, have demonstrated in vitro activity against P. aeruginosa strains. Here we show that the mammalian PR-AMP Bac7(1-35) is active against some multidrug-resistant cystic fibrosis isolates of P. aeruginosa. By confocal microscopy and cytometric analyses, we investigated the mechanism of killing against P. aeruginosa strain PAO1 and three selected isolates, and we observed that the peptide inactivated the target cells by disrupting their cellular membranes. This effect is deeply different from that previously described for PR-AMPs in Escherichia coli and Salmonella enterica serovar Typhimurium, where these peptides act intracellularly after having been internalized by means of the transporter SbmA without membranolytic effects. The heterologous expression of SbmA in PAO1 cells enhanced the internalization of Bac7(1-35) into the cytoplasm, making the bacteria more susceptible to the peptide but at the same time more resistant to the membrane lysis, similarly to what occurs in E. coli. The results evidenced a new mechanism of action for PRAMPs and indicate that Bac7 has multiple and variable modes of action that depend on the characteristics of the different target species and the possibility to be internalized by bacterial transporters. This feature broadens the spectrum of activity of the peptide and makes the development of peptide-resistant bacteria a more difficult process.

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“…Antimicrobial peptides inhibiting bacterial growth by depolarizing the membrane, such as the cecropins and magainins fall short in one or more of these categories. In particular, excessive activity on bacterial membranes often goes hand in hand with toxicity to mammalian cells (Bower et al 2003). We also speculated that bacteria can alter their membrane composition to evade the activity of membrane-acting antimicrobial peptides .…”

Section: Additional Pharmacological Parameters: Toxicity Stability mentioning

confidence: 98%

“…Bower et al 2003). The minor alteration in the K d figure from assay to assay reflects solubility problems of pyrrhocoricin -DnaK protein complexes during in vitro biological assay conditions (Chesnokova et al 2004).…”

Section: Dnak Bindingmentioning

confidence: 99%

“…These properties are likely due to the more robust pharmacophore of pyrrhocoricin and the more potent cell-penetrating domain of drosocin, at least at the monomeric peptide level (Bencivengo et al 2001). Slight changes in the peptide sequence, all including incorporation of additional positively charged amino acid residues, can change pyrrhocoricin's predominant mode of action from DnaK inhibition to membrane disintegration (Bencivengo et al 2001;Bower et al 2003). The additional positive charges promote interaction of the peptide with bacterial membranes to a point when harmless cell penetration turns into membrane depolarization.…”

Section: Introductionmentioning

confidence: 99%

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Chimeric Antimicrobial Peptides Exhibit Multiple Modes of Action

Ötvös

Snyder

Condie

et al. 2005

Int J Pept Res Ther

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Pyrrhocoricin and drosocin, representatives of the short, proline-rich antimicrobial peptide family kill bacteria by inactivating the bacterial heat shock protein DnaK and inhibiting chaperone-assisted protein folding. The molecular architecture of these peptides features an N-terminal DnaK-binding half and a C-terminal delivery unit, capable of crossing bacterial membranes. Cell penetration is enhanced if multiple copies of pyrrhocoricin are conjugated. To obtain drug leads with improved antimicrobial properties, and possible utility as therapeutic agents, we synthesized chimeric dimers, in which pyrrhocoricin's potent DnaK-binding domain was connected to drosocin's superior cell penetrating module. Indeed, the new constructs not only exhibited enhanced in vitro antibacterial properties against the originally sensitive strains Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium, but also showed activity against Staphylococcus aureus, a bacterial strain resistant to native pyrrhocoricin and drosocin. The improved antimicrobial profile could be demonstrated with assays designed to distinguish intracellular or membrane activities. While a novel mixed pyrrhocoricin-drosocin dimer and the purely pyrrhocoricinbased old dimer bound E. coli DnaK with an identical 4 lM K d , the mixed dimers penetrated a significantly larger number of E. coli and S. aureus cells than the previous analogs and destroyed a larger percentage of bacterial membrane structures. Toxicity to human red blood cells could not be observed up to the highest peptide concentration tested, 640 lM. In addition, repetitive reculturing of E. coli or S. aureus cells with sublethal concentrations of the mixed dimer did not result in resistance induction to the novel peptide antibiotic. The new concept of pyrrhocoricin-drosocin mixed dimers yields antibacterial peptide derivatives acting with a multiple mode of action, and can serve as a useful addition to the current antimicrobial therapy repertoire.

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Walking the fine line between intracellular and membrane activities of antibacterial peptides

Cited by 8 publications

References 40 publications

An Insect Antibacterial Peptide-Based Drug Delivery System

An Insect Antibacterial Peptide-Based Drug Delivery System

The Mechanism of Killing by the Proline-Rich Peptide Bac7(1–35) against Clinical Strains of Pseudomonas aeruginosa Differs from That against Other Gram-Negative Bacteria

Chimeric Antimicrobial Peptides Exhibit Multiple Modes of Action

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