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2000
Hetru Charles, Letellier L, Oren Z, Hoffmann Jules A, Shai Y
Androctonin, a hydrophilic disulphide-bridged non-haemolytic anti-microbial peptide: a plausible mode of action Journal Article
In: Biochem. J., vol. 345 Pt 3, pp. 653–664, 2000, ISSN: 0264-6021.
Abstract | BibTeX | Tags: Adenosine Triphosphate, Anti-Bacterial Agents, Cations, Cell Membrane Permeability, Cytoplasm, Disulfides, Electron, Escherichia coli, Fluoresceins, Fluorescent Dyes, Fourier Transform Infrared, Gram-Negative Bacteria, hoffmann, Insect Proteins, Liposomes, M3i, Microbial Sensitivity Tests, Micrococcus luteus, Microscopy, oxygen, Phospholipids, Potassium, Proteins, spectroscopy
@article{hetru_androctonin_2000,
title = {Androctonin, a hydrophilic disulphide-bridged non-haemolytic anti-microbial peptide: a plausible mode of action},
author = {Charles Hetru and L Letellier and Z Oren and Jules A Hoffmann and Y Shai},
issn = {0264-6021},
year = {2000},
date = {2000-01-01},
journal = {Biochem. J.},
volume = {345 Pt 3},
pages = {653--664},
abstract = {Androctonin is a 25-residue non-haemolytic anti-microbial peptide isolated from the scorpion Androctonus australis and contains two disulphide bridges. Androctonin is different from known native anti-microbial peptides, being a relatively hydrophilic and non-amphipathic molecule. This raises the possibility that the target of androctonin might not be the bacterial membrane, shown to be a target for most amphipathic lytic peptides. To shed light on its mode of action on bacteria and its non-haemolytic activity, we synthesized androctonin, its fluorescent derivatives and its all-D-amino acid enantiomer. The enantiomer preserved high activity, suggesting a lipid-peptide interaction between androctonin and bacterial membranes. In Gram-positive and (at higher concentrations) Gram-negative bacteria, androctonin induced an immediate perturbation of the permeability properties of the cytoplasmic membrane of the bacterial energetic state, concomitant with perturbation of the morphology of the cell envelope as revealed by electron microscopy. Androctonin binds only to negatively charged lipid vesicles and induces the leakage of markers at high concentrations and with a slow kinetics, in contrast with amphipathic alpha-helical anti-microbial peptides that bind and permeate negatively charged vesicles, and to a smaller extent also zwitterionic ones. This might explain the selective lytic activity of androctonin towards bacteria but not red blood cells. Polarized attenuated total reflection-Fourier transform infrared spectroscopy revealed that androctonin adopts a beta-sheet structure in membranes and did not affect the lipid acyl chain order, which supports a detergent-like effect. The small size of androctonin, its hydrophilic character and its physicochemical properties are favourable features for its potential application as a replacement for commercially available antibiotics to which bacteria have developed resistance.},
keywords = {Adenosine Triphosphate, Anti-Bacterial Agents, Cations, Cell Membrane Permeability, Cytoplasm, Disulfides, Electron, Escherichia coli, Fluoresceins, Fluorescent Dyes, Fourier Transform Infrared, Gram-Negative Bacteria, hoffmann, Insect Proteins, Liposomes, M3i, Microbial Sensitivity Tests, Micrococcus luteus, Microscopy, oxygen, Phospholipids, Potassium, Proteins, spectroscopy},
pubstate = {published},
tppubtype = {article}
}
Androctonin is a 25-residue non-haemolytic anti-microbial peptide isolated from the scorpion Androctonus australis and contains two disulphide bridges. Androctonin is different from known native anti-microbial peptides, being a relatively hydrophilic and non-amphipathic molecule. This raises the possibility that the target of androctonin might not be the bacterial membrane, shown to be a target for most amphipathic lytic peptides. To shed light on its mode of action on bacteria and its non-haemolytic activity, we synthesized androctonin, its fluorescent derivatives and its all-D-amino acid enantiomer. The enantiomer preserved high activity, suggesting a lipid-peptide interaction between androctonin and bacterial membranes. In Gram-positive and (at higher concentrations) Gram-negative bacteria, androctonin induced an immediate perturbation of the permeability properties of the cytoplasmic membrane of the bacterial energetic state, concomitant with perturbation of the morphology of the cell envelope as revealed by electron microscopy. Androctonin binds only to negatively charged lipid vesicles and induces the leakage of markers at high concentrations and with a slow kinetics, in contrast with amphipathic alpha-helical anti-microbial peptides that bind and permeate negatively charged vesicles, and to a smaller extent also zwitterionic ones. This might explain the selective lytic activity of androctonin towards bacteria but not red blood cells. Polarized attenuated total reflection-Fourier transform infrared spectroscopy revealed that androctonin adopts a beta-sheet structure in membranes and did not affect the lipid acyl chain order, which supports a detergent-like effect. The small size of androctonin, its hydrophilic character and its physicochemical properties are favourable features for its potential application as a replacement for commercially available antibiotics to which bacteria have developed resistance.
1991
Lepage P, Bitsch F, Roecklin D, Keppi E, Dimarcq Jean-Luc, Reichhart Jean-Marc, Hoffmann Jules A, Roitsch C, Dorsselaer Van A
Determination of disulfide bridges in natural and recombinant insect defensin A Journal Article
In: Eur. J. Biochem., vol. 196, no. 3, pp. 735–742, 1991, ISSN: 0014-2956.
Abstract | BibTeX | Tags: Animals, Blood Proteins, Defensins, Diptera, Disulfides, Hemolymph, hoffmann, M3i, Mass Spectrometry, Recombinant Proteins, reichhart
@article{lepage_determination_1991,
title = {Determination of disulfide bridges in natural and recombinant insect defensin A},
author = {P Lepage and F Bitsch and D Roecklin and E Keppi and Jean-Luc Dimarcq and Jean-Marc Reichhart and Jules A Hoffmann and C Roitsch and Van A Dorsselaer},
issn = {0014-2956},
year = {1991},
date = {1991-01-01},
journal = {Eur. J. Biochem.},
volume = {196},
number = {3},
pages = {735--742},
abstract = {The primary-structure comparison of natural insect defensin A from Phormia terranovae and recombinant insect defensin A from Saccharomyces cerevisiae has been accomplished using a combination of Edman degradation and liquid secondary ion mass spectrometry. The natural and recombinant proteins have the same primary structure with identical disulfide-bond designations (formula; see text) as determined from the peptides obtained after thermolysin digestion. The combined use of Edman degradation and mass spectometry allowed the disulfide-bridge structure to be determined with a total of only 40 micrograms (9.9 nmol) natural peptide. Mass spectrometry provides a rapid means of disulfide-bridge verification, requiring not more than 20 micrograms recombinant insect defensin A, which is compatible with use in batch analysis.},
keywords = {Animals, Blood Proteins, Defensins, Diptera, Disulfides, Hemolymph, hoffmann, M3i, Mass Spectrometry, Recombinant Proteins, reichhart},
pubstate = {published},
tppubtype = {article}
}
The primary-structure comparison of natural insect defensin A from Phormia terranovae and recombinant insect defensin A from Saccharomyces cerevisiae has been accomplished using a combination of Edman degradation and liquid secondary ion mass spectrometry. The natural and recombinant proteins have the same primary structure with identical disulfide-bond designations (formula; see text) as determined from the peptides obtained after thermolysin digestion. The combined use of Edman degradation and mass spectometry allowed the disulfide-bridge structure to be determined with a total of only 40 micrograms (9.9 nmol) natural peptide. Mass spectrometry provides a rapid means of disulfide-bridge verification, requiring not more than 20 micrograms recombinant insect defensin A, which is compatible with use in batch analysis.
