par Brasseur, Robert 
;Cabiaux, Véronique ;Falmagne, Paul ;Ruysschaert, Jean Marie
Référence Biochemical and biophysical research communications, 136, 1, page (160-168)
Publication Publié, 1986-04
;Cabiaux, Véronique ;Falmagne, Paul ;Ruysschaert, Jean Marie Référence Biochemical and biophysical research communications, 136, 1, page (160-168)
Publication Publié, 1986-04
Article révisé par les pairs
| Résumé : | A peptide of diphtheria toxin B fragment (residues 147-266) has been shown to induce pore formation in lipid bilayer membranes at low pH. Such an effect was obtained at a much lower extent or not at all at pH = 7. The region localized between residues 225 and 246 is highly hydrophobic (27.3% polarity) and characterized by a high concentration of proline residues. Since proline cis-trans isomerization is highly sensitive to the pH of the medium, we investigated the capability of the cis and trans isomers to penetrate into the lipid matrix. Obviously, the cis-trans isomerization of proline 242 and 245, assumed to be imposed by a low pH, uncovers the hydrophobic region and induces its insertion into a lipid layer of dipalmitoylphosphatidylcholine. The lipid matrix destabilization resulting from this process could promote the penetration into the lipid bilayer of an amphipatic structure (153-178) similar to the transverse lipid associating domains of membrane proteins. |
