Locating intercalants within lipid bilayers using fluorescence quenching by bromophospholipids and iodophospholipids
作者:Carmit Alexenberg、Michal Afri、Shlomi Eliyahu、Hani Porat、Ayala Ranz、Aryeh A. Frimer
DOI:10.1016/j.chemphyslip.2019.03.018
日期:2019.7
fluorescent moiety. We have synthesized various phospholipids with bromine (or iodine) atoms substituted at various locations along the lipid chain. The latter halolipids were intercalated in turn with various fluorophores into DMPC liposomes, biomembranes and erythrocyte ghosts. The most effective fluorescence quenching occurs when the heavy atom location corresponds to that of the fluorophore. The
在以前的工作中,我们已经可以使用三种光谱技术的溶剂极性敏感性来确定脂质双层中插入分子的深度:13 C NMR化学位移(δ);荧光发射波长(λem)和ESRβ-H分裂常数(aβ-H)。在本文中,我们使用位于磷脂链已知位置的重原子(Br或I)淬灭作为荧光部分位置的探针。我们已经合成了在脂质链的各个位置上都被溴(或碘)原子取代的各种磷脂。后面的类脂与各种荧光基团依次插入DMPC脂质体,生物膜和红细胞鬼影。当重原子的位置与荧光团的位置相对应时,会发生最有效的荧光猝灭。结果表明,一般而言,荧光团插入相同的深度,而与所使用的脂质双层无关。当荧光团位于水相中或水相中时,KBr(或KI)是最有效的淬灭剂。据推测,由于碘的半径较大和自旋耦合常数较大,因此碘类似物在其淬灭的深度范围内的分辨力要小得多。