%0 Journal Article
%A Alegre Cebollada, Jorge
%A Martínez Del Pozo, Álvaro
%A Gavilanes, José G.
%A Goormaghtigh, Erik
%T Infrared spectroscopy study on the conformational changes leading to pore formation of the toxin Sticholysin II
%D 2007
%@ 1542-0086
%U https://hdl.handle.net/20.500.14352/52856
%X The structure of the actinoporin sticholysin II (StnII) in the pore state was investigated by Fourier transform infraredspectroscopy in the attenuated total reflection configuration. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine/cholesterol unilamellarvesicles were employed. The a-helix content increases in;30% upon lipid binding, which agrees with an extension of eightor nine residues at the N-terminal helix. Furthermore, analyses of dichroic spectra show that the extended N-terminal helix wouldhave a 31º tilt with respect to the membrane normal. The orientation of the central beta-sandwich was also estimated. In addition, it wasdetected that StnII alters the orientation of the lipid acyl chains. 1H/2Hexchange experiments sustain a mainly superficial interactionbetween StnII and the membrane, with no protection of the beta-sandwich. The implications of the results in the mechanism of poreformation are discussed.
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