Fluorescent, Synthetic Amphiphilic Heptapeptide Anion Transporters: Evidence for Self‐Assembly and Membrane Localization in Liposomes
作者:Lei You、George W. Gokel
DOI:10.1002/chem.200800147
日期:2008.6.27
Synthetic anion transporters (SATs) of the general type (n-C18H37)2N-COCH2OCH2CO-(Gly)3-Pro-(Gly)3-O-n-C7H15, 1, are amphiphilic peptides that form anion-conducting pores in bilayer membranes. To better understand membrane insertion, assembly and aggregation dynamics, and membrane penetration, four novel fluorescent structures were prepared for use in both aqueous buffer and phospholipid bilayers.
一般类型 (n-C18H37)2N-COCH2OCH2CO-(Gly)3-Pro-(Gly)3-On-C7H15, 1 的合成阴离子转运蛋白 (SAT) 是两亲性肽,在双层膜中形成阴离子传导孔。为了更好地了解膜插入、组装和聚集动力学以及膜渗透,制备了四种新型荧光结构,用于水性缓冲液和磷脂双层。将荧光残基芘、吲哚、丹酰基和NBD掺入1中,分别得到2、3、4和5。通过监测 2 观察到的芘单体/准分子峰的变化,证实了缓冲液中肽两亲物的组装。双层中吲哚 (3) 和丹磺酰 (4) 侧链 SAT 观察到的溶剂依赖性荧光变化表明,这些残基经历了极性介于 epsilon=9 (CH2Cl2) 和 epsilon=24 (EtOH) 之间的环境。 2 和 3 之间的荧光共振能量转移 (FRET) 表明 SAT 单体在双层内聚集。这种自组装导致孔的形成,这被检测为 Cl(-) 从脂质体中释放。荧光 SAT 的丙烯酰胺猝灭结果支持膜插入。