caa a22 4500 477137490 CHVBK 20180405111723.0 cr unu---uuuuu 170330e19971201xx s 000 0 eng 10.1023/A:1008818732003 doi (NATIONALLICENCE)springer-10.1023/A:1008818732003 α-Helix to β-sheet transition within the LeuiLysj (i [Elektronische Daten] 2j) series of lytic amphipathic peptides by decreasing their size [Sabine Castano, Bernard Desbat, Isabelle Cornut, Philippe Méléard, Jean Dufourcq] De novo designed extremely simplified amphipathic basicLeuiLysj (i = 2j) peptides of 8, 9 and 15residues were synthesized to clarify the mechanism of action of naturalcytotoxic and hemolytic small proteins or peptides. They proved to havestrong hemolytic activity towards human erythrocytes which increases withpeptide length. These peptides are highly surface active and form stablepeptidic films at the air/water interface. The sensitive and efficient FTIRmodulated polarization technique (PMIRRAS) allows one to obtain in situstructural and orientational information about the peptides at theinterface. A transition of secondary structure is observed: the shorterpeptides (8 and 9 residues) adopt β-sheet structures while the longerone (15 residues) is folded into an α-helix. In both cases, the peptideslie with the axis parallel to the interface. Their insertion into adimyristoylphosphatidylcholine monolayer can be followed from the increasein the surface and/or pressure of the films. In the mixed films, thepeptides adopt the same structure and orientation as observed at theair/water interface. Therefore, among the same series of peptides, atransition from β-sheet to α-helix occurs when the length increases(roughly >10 aa), but despite this drastic change both types ofstructures result in strongly hemolytic peptides. Kluwer Academic Publishers, 1997 Hemolysis nationallicence Monolayers nationallicence PMIRRAS nationallicence Castano Sabine CRPP-CNRS, Avenue A. Schweitzer, F-33600, Pessac, France aut Desbat Bernard LSMC, Université de Bordeaux I, F-33400, Talence, France aut Cornut Isabelle Fournier Pharma GmbH, D-69123, Heidelberg, Germany aut Méléard Philippe CRPP-CNRS, Avenue A. Schweitzer, F-33600, Pessac, France aut Dufourcq Jean CRPP-CNRS, Avenue A. Schweitzer, F-33600, Pessac, France aut Letters in Peptide Science Kluwer Academic Publishers 4/4-6(1997-12-01), 195-200 0929-5666 4:4-6<195 1997 4 10989 https://doi.org/10.1023/A:1008818732003 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1008818732003 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Castano Sabine CRPP-CNRS, Avenue A. Schweitzer, F-33600, Pessac, France aut NATIONALLICENCE 700 1- Desbat Bernard LSMC, Université de Bordeaux I, F-33400, Talence, France aut NATIONALLICENCE 700 1- Cornut Isabelle Fournier Pharma GmbH, D-69123, Heidelberg, Germany aut NATIONALLICENCE 700 1- Méléard Philippe CRPP-CNRS, Avenue A. Schweitzer, F-33600, Pessac, France aut NATIONALLICENCE 700 1- Dufourcq Jean CRPP-CNRS, Avenue A. Schweitzer, F-33600, Pessac, France aut NATIONALLICENCE 773 0- Letters in Peptide Science Kluwer Academic Publishers 4/4-6(1997-12-01), 195-200 0929-5666 4:4-6<195 1997 4 10989 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 477137490 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer