Publications
2003
Lancelot Nathalie, Elbayed Karim, Raya Jésus, Piotto Martial, Briand Jean-Paul, Formaggio Fernando, Toniolo Claudio, Bianco Alberto
Characterization of the 310-helix in model peptides by HRMAS NMR spectroscopy Journal Article
In: Chemistry (Weinheim an Der Bergstrasse, Germany), vol. 9, no. 6, pp. 1317–1323, 2003, ISSN: 0947-6539.
Abstract | Links | BibTeX | Tags: biomolecular, Fourier Transform Infrared, I2CT, Nuclear Magnetic Resonance, Peptides, Protein Conformation, spectroscopy, Team-Bianco
@article{lancelot_characterization_2003,
title = {Characterization of the 310-helix in model peptides by HRMAS NMR spectroscopy},
author = {Nathalie Lancelot and Karim Elbayed and Jésus Raya and Martial Piotto and Jean-Paul Briand and Fernando Formaggio and Claudio Toniolo and Alberto Bianco},
doi = {10.1002/chem.200390151},
issn = {0947-6539},
year = {2003},
date = {2003-03-01},
journal = {Chemistry (Weinheim an Der Bergstrasse, Germany)},
volume = {9},
number = {6},
pages = {1317--1323},
abstract = {A tetra- and a hepta-homopeptide from the C(alpha)-tetrasubstituted Aib (alpha-aminoisobutyric acid) residue were covalently linked to the POEPOP resin by the fragment-condensation approach. The conformational preferences of the two model peptides were determined for the first time on a solid support by means of high-resolution magic angle spinning NMR spectroscopy. The results obtained indicate that the Aib homopeptides adopt a regular 3(10)-helical structure even when they are covalently bound to a polymeric matrix, and thus confirm the remarkable conformational stability of the peptides rich in this amino acid. An ATR-FTIR spectroscopic investigation, performed in parallel, also confirmed that these polymer-bound peptides do indeed adopt a helical conformation. The results of this study open the possibility to exploit the peptide-resin conjugates based on C(alpha)-tetrasubstituted alpha-amino acids as helpful, structurally organized templates in molecular recognition studies or as catalysts in asymmetric synthesis.},
keywords = {biomolecular, Fourier Transform Infrared, I2CT, Nuclear Magnetic Resonance, Peptides, Protein Conformation, spectroscopy, Team-Bianco},
pubstate = {published},
tppubtype = {article}
}
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}
}