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 Article de journal
Dans: Biochem. J., vol. 345 Pt 3, p. 653–664, 2000, ISSN: 0264-6021.
Résumé | BibTeX | Étiquettes: 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}
}
Auble D T, Hansen K E, Mueller C G, Lane W S, Thorner J, Hahn S
Mot1, a global repressor of RNA polymerase II transcription, inhibits TBP binding to DNA by an ATP-dependent mechanism Article de journal
Dans: Genes & Development, vol. 8, no. 16, p. 1920–1934, 1994, ISSN: 0890-9369.
Résumé | Liens | BibTeX | Étiquettes: Adenosine Triphosphatases, Adenosine Triphosphate, Amino Acid Sequence, Base Sequence, Biological, DNA, DNA Helicases, DNA Probes, DNA-Binding Proteins, Fungal, Fungal Proteins, Genes, Genetic, Models, Molecular Sequence Data, Mutagenesis, Repressor Proteins, RNA Polymerase II, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Site-Directed, TATA Box, TATA-Binding Protein Associated Factors, TATA-Box Binding Protein, Team-Mueller, Transcription, Transcription Factors
@article{auble_mot1_1994,
title = {Mot1, a global repressor of RNA polymerase II transcription, inhibits TBP binding to DNA by an ATP-dependent mechanism},
author = {D T Auble and K E Hansen and C G Mueller and W S Lane and J Thorner and S Hahn},
doi = {10.1101/gad.8.16.1920},
issn = {0890-9369},
year = {1994},
date = {1994-08-01},
journal = {Genes & Development},
volume = {8},
number = {16},
pages = {1920--1934},
abstract = {Basal transcription of many genes in yeast is repressed by Mot1, an essential protein which is a member of the Snf2/Swi2 family of conserved nuclear factors. ADI is an ATP-dependent inhibitor of TATA-binding protein (TBP) binding to DNA that inhibits transcription in vitro. Here we demonstrate that ADI is encoded by the MOT1 gene. Mutation of MOT1 abolishes ADI activity and derepresses basal transcription in vitro and in vivo. Recombinant Mot1 removes TBP from DNA and Mot1 contains an ATPase activity which is essential for its function. Genetic interactions between Mot1 and TBP indicate that their functions are interlinked in vivo. These results provide a general model for understanding the mechanism of action of a large family of nuclear factors involved in processes such as transcription and DNA repair.},
keywords = {Adenosine Triphosphatases, Adenosine Triphosphate, Amino Acid Sequence, Base Sequence, Biological, DNA, DNA Helicases, DNA Probes, DNA-Binding Proteins, Fungal, Fungal Proteins, Genes, Genetic, Models, Molecular Sequence Data, Mutagenesis, Repressor Proteins, RNA Polymerase II, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Site-Directed, TATA Box, TATA-Binding Protein Associated Factors, TATA-Box Binding Protein, Team-Mueller, Transcription, Transcription Factors},
pubstate = {published},
tppubtype = {article}
}