n-Alcohol Length Governs Shift in L(o)-L(d) Mixing Temperatures in Synthetic and Cell-Derived Membranes.
n-Alcohol Length Governs Shift in L(o)-L(d) Mixing Temperatures in Synthetic and Cell-Derived Membranes.
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DOI：
10.1016/j.bpj.2017.06.066
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发表时间：
2017-09-19
影响因子：
3.4
通讯作者：
Keller SL
中科院分区：
文献类型：
--
作者：
Cornell CE;McCarthy NLC;Levental KR;Levental I;Brooks NJ;Keller SL
膜生物物理学中的持续挑战是定量预测膜物理性质在添加新的两亲物（例如，脂质、醇类、肽类或蛋白质），以评估这些变化是否足够大，足以导致生物学后果。由于它们作为全身麻醉剂的作用，正醇可能是这类两亲物中研究得最好的。当n-醇被添加到模型和细胞膜，膜参数的变化往往是适度的。一个显着的例外是发现在液-液溶解性转变温度（Tmix）的大幅度下降时，观察到短链的n-醇被纳入巨质膜囊泡（GPMV）。在GPMV以及由具有低熔化温度的脂质、具有高熔化温度的脂质和胆固醇的三元混合物组成的巨型单层囊泡（GUV）中，在低于Tmix的温度下观察到共存的液体有序相和液体无序相。在这里，我们发现，当在短链正醇（n ≤ 10）的水溶液中形成典型三元混合物的GUV时，Tmix相对于水中的GUV增加。这种变化与细胞来源的GPMV报道的方向相反。Tmix的增加在几种类型的脂质、脂质比率、短链n-醇的类型和n-醇的浓度的GUV中是稳健的。然而，随着正醇链长的增加，观察到Tmix的非单调变化。具有10-14个碳的链长的醇降低二油酰-PC/二棕榈酰-PC/胆固醇的三元GUV中的Tmix，而16个碳再次增加Tmix。Gray等人观察到了类似的影响的长度的正醇的方向上的转变Tmix。这些结果是一致的情况下，在液体有序和液体无序相之间的相对分区的n-醇的n-醇的链长的增加而演变。
A persistent challenge in membrane biophysics has been to quantitatively predict how membrane physical properties change upon addition of new amphiphiles (e.g., lipids, alcohols, peptides, or proteins) in order to assess whether the changes are large enough to plausibly result in biological ramifications. Because of their roles as general anesthetics, n-alcohols are perhaps the best-studied amphiphiles of this class. When n-alcohols are added to model and cell membranes, changes in membrane parameters tend to be modest. One striking exception is found in the large decrease in liquid-liquid miscibility transition temperatures (Tmix) observed when short-chain n-alcohols are incorporated into giant plasma membrane vesicles (GPMVs). Coexisting liquid-ordered and liquid-disordered phases are observed at temperatures below Tmix in GPMVs as well as in giant unilamellar vesicles (GUVs) composed of ternary mixtures of a lipid with a low melting temperature, a lipid with a high melting temperature, and cholesterol. Here, we find that when GUVs of canonical ternary mixtures are formed in aqueous solutions of short-chain n-alcohols (n ≤ 10), Tmix increases relative to GUVs in water. This shift is in the opposite direction from that reported for cell-derived GPMVs. The increase in Tmix is robust across GUVs of several types of lipids, ratios of lipids, types of short-chain n-alcohols, and concentrations of n-alcohols. However, as chain lengths of n-alcohols increase, nonmonotonic shifts in Tmix are observed. Alcohols with chain lengths of 10–14 carbons decrease Tmix in ternary GUVs of dioleoyl-PC/dipalmitoyl-PC/cholesterol, whereas 16 carbons increase Tmix again. Gray et al. observed a similar influence of the length of n-alcohols on the direction of the shift in Tmix. These results are consistent with a scenario in which the relative partitioning of n-alcohols between liquid-ordered and liquid-disordered phases evolves as the chain length of the n-alcohol increases.
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DOI：
10.1016/0005-2736(81)90256-x
发表时间：
1981-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
HORNBY, AP;CULLIS, PR
通讯作者：
CULLIS, PR
DOI：
10.1016/0005-2736(81)90017-1
发表时间：
1981-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
JANOFF, AS;PRINGLE, MJ;MILLER, KW
通讯作者：
MILLER, KW
影响因子：
2.9
作者：
BARRY, JA;GAWRISCH, K
通讯作者：
GAWRISCH, K
DOI：
10.1073/pnas.0908987106
发表时间：
2009-09-29
影响因子：
11.1
作者：
Kaiser, Hermann-Josef;Lingwood, Daniel;Simons, Kai
通讯作者：
Simons, Kai
影响因子：
3.7
作者：
Gray EM;Díaz-Vázquez G;Veatch SL
通讯作者：
Veatch SL