Synthesis of Model Amphipathic Cyclic Peptides and their Potential to Induce Leakage in Liposomes

[409873] Ngu-Schwemlein路易斯安那州立大学PI: Ngu-Schwemlein路易斯安那州立大学将合成具有交替的D-和l -氨基酸残基的环状两亲八肽。这些多肽的相反极性面将作为磷脂双层相互作用的模型进行研究。将制备Cyclo (L-Xxx-D-Xxx)2-(L-Leu-D-Leu)2，其中X = Ser， Lys或Glu，并通过NMR和高分辨率质谱进行表征。这些环状肽诱导磷脂双层渗漏的潜力将通过测量由于脂质体渗漏而引起的羧基荧光素荧光强度的变化来探索。这项研究计划资助来自化学部门，支持路易斯安那州立大学Maria Ngu-Schwemlein教授的研究。将制备具有交替的D-和L-氨基酸残基的环状肽。这些分子具有交替的“右手”和“左手”氨基酸残基结合成环状阵列，将用光谱方法表征。在这些环肽类中，相互作用的对立带电残基环有望显示出独特的物理性质。这些肽在生物学上重要的磷脂膜中诱导泄漏的可能性将被探索。

9409873 Ngu-Schwemlein Louisiana State University PI: Ngu-Schwemlein Louisiana State University Cyclic amphipathic octapeptides with alternating D- and L-amino acid residues will be synthesized. The opposing polarity faces in these peptides will be studied as models for interactions in phospholipid bi-layers. Cyclo (L-Xxx-D-Xxx)2-(L-Leu-D-Leu)2 , where X = Ser, Lys or Glu, will be prepared and characterized by NMR and high resolution mass spectroscopy. The potential of these cyclic peptides to induce leakage in a phospholipid bi-layer will be explored by measuring the change in fluorescence intensity of carboxyfluorescein due to leakage from liposomes. This Research Planning Grant from the Chemistry Division supports the research of Professor Maria Ngu-Schwemlein at Louisiana State University. Cyclic peptides with alternating D- and L- amino acid residues will be prepared. These molecules that have alternating "right hand" and "left hand" amino acid residues bonded into a cyclic array will be characterized by spectroscopic methods. Interactions across the ring of opposing charged residues is expected to display unique physical properties in these cyclic peptides. The possibility of these peptides inducing leakage in biologically important phospholipid membranes will be explored.