caa a22 4500 477138039 CHVBK 20180405111724.0 cr unu---uuuuu 170330e19971201xx s 000 0 eng 10.1007/BF02442875 doi (NATIONALLICENCE)springer-10.1007/BF02442875 α-Helix to β-sheet transition within the Leu i Lys j (i=2j) series of lytic amphipathic peptides by decreasing their size [Elektronische Daten] [Sabine Castano, Bernard Desbat, Isabelle Cornut, Philippe Méléard, Jean Dufourcq] Summary: De novo designed extremely simplified amphipathic basic LeuiLysj (i=2j) peptides of 8, 9 and 15 residues were synthesized to clarify the mechanism of action of natural cytotoxic and hemolytic small proteins or peptides. They proved to have strong hemolytic activity towards human erythrocytes which increases with peptide length. These peptides are highly surface active and form stable peptidic films at the air/water interface. The sensitive and efficient FTIR modulated polarization technique (PMIRRAS) allows one to obtain in situ structural and orientational information about the peptides at the interface. A transition of secondary structure is observed: the shorter peptides (8 and 9 residues) adopt β-sheet structures while the longer one (15 residues) is folded into an α-helix. In both cases, the peptides lie with the axis parallel to the interface. Their insertion into a dimyristoylphosphatidylcholine monolayer can be followed from the increase in the surface and/or pressure of the films. In the mixed films, the peptides adopt the same structure and orientation as observed at the air/water interface. Therefore, among the same series of peptides, a transition from β-sheet to α-helix occurs when the length increases (roughly>10 aa), but despite this drastic change both types of structures 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/10.1007/BF02442875 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02442875 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