Laurdan and di-4-ANEPPDHQ do not respond to membrane-inserted peptides and are good probes for lipid packing
Laurdan and di-4-ANEPPDHQ do not respond to membrane-inserted peptides and are good probes for lipid packing
复制标题
DOI：
10.1016/j.bbamem.2010.10.002
复制
发表时间：
2011-01-01
影响因子：
3.4
通讯作者：
Parmryd, Ingela
中科院分区：
文献类型：
--
作者：
Dinic, Jelena;Biverstahl, Henrik;Parmryd, Ingela
用Laurdan和di-4-ANEPPDHQ作为膜有序化的探针，相对于液无序(LD)相的膜，液相(Lo)膜的发射发生了蓝移。它们作为膜有序探针的使用要求它们的光谱位移不受膜蛋白的影响，我们已经使用膜插入肽和大单层囊泡(LuV)对其进行了研究。将跨膜多肽--马斯多兰和牛普鲁恩蛋白衍生肽(BPrPp)分别加入到L0或Ld相的LV中，使其与总脂的比例达到1：10。在两种脂相中，Laurdan和di-4-ANEPPDHQ的激发光谱和发射光谱不受多肽的影响。用动态光散射法测定加入多肽后LuV的完整性和大小分布。通过圆二色谱测量多肽的二级结构，确定多肽在LuV中的插入效率。Mastoparan具有α-螺旋和bPrPp，β-链构象与插入到脂质双层中相容。我们的结果表明，生物膜中蛋白质的存在不会影响Laurdan和di-4-ANEPPDHQ的光谱，支持这两种染料是评估细胞内脂质顺序的合适探针。(C)2010爱思唯尔B.V.保留所有权利。
Laurdan and di-4-ANEPPDHQ are used as probes for membrane order, with a blue shift in emission for membranes in liquid-ordered (lo) phase relative to membranes in liquid-disordered (ld) phase. Their use as membrane order probes requires that their spectral shifts are unaffected by membrane proteins, which we have examined by using membrane inserting peptides and large unilamellar vesicles (LUVs). The transmembrane polypeptides, mastoparan and bovine prion protein-derived peptide (bPrPp), were added to LUVs of either lo or ld phase, up to 1:10 peptide/total lipid ratio. The excitation and emission spectra of laurdan and di-4-ANEPPDHQ in both lipid phases were unaltered by peptide addition. The integrity and size distribution of the LUVs upon addition of the polypeptides were determined by dynamic light scattering. The insertion efficiency of the polypeptides into LUVs was determined by measuring their secondary structure by circular dichroism. Mastoparan had an alpha-helical and bPrPp a beta-strand conformation compatible with insertion into the lipid bilayer. Our results suggest that the presence of proteins in biological membranes does not influence the spectra of laurdan and di-4-ANEPPDHQ supporting that the dyes are appropriate probes for assessing lipid order in cells. (C) 2010 Elsevier B.V. All rights reserved.