Regensburg 2010 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 28: Poster: Biopolymers and Biomaterials
CPP 28.6: Poster
Mittwoch, 24. März 2010, 17:30–19:00, Poster C
2H NMR Studies on Acylated Transmembrane Fusion Peptides — •Anja Penk1, Matthias Müller1, Holger Scheidt1,2, Dieter Langosch3, and Daniel Huster1 — 1Institut für Medizinische Physik und Biophysik, Universität Leipzig, Leipzig, D — 2Institut für Biochemie/Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Halle, D — 3Lehrstuhl Chemie der Biopolymere, Technische Universität München, Freising, D
Fusion of biological membranes is mediated by integral membrane proteins, often modified by covalent attached hydrocarbon chains. Previously, a series of de novo designed alpha-helical peptides with mixed Leu/Val sequences was presented, mimicking fusogenic transmembrane segments. From this series, we have investigated the peptide LV16 (KKKWL VLVLV LVLVL VLVLV KKK), which was synthesized presenting either a free N-terminus or an N-acylation of 2, 8, 12, or 16 carbons. We used 2H and 31P NMR to investigate the structure and dynamics of these peptide lipid chains in POPC and DLPC bilayers and compared them to the hydrocarbon chains of the surrounding membrane. Except for the C-2 chain, all peptide acyl chains were found to insert well into the membrane. This can be understood from the high local lipid concentration, which the N-terminal lipid chains experience. The insertion of these peptides did not influence the membrane structure and dynamics. Although the longer acyl chains insert into the membrane, there is no length adaptation. In spite of the significantly different lengths of the acyl chains, the fraction of gauche defects in the inserted chains is constant, suggesting similar chain entropies.