Investigation of the domain line tension in asymmetric vesicles prepared via hemifusion.
Investigation of the domain line tension in asymmetric vesicles prepared via hemifusion.
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DOI：
10.1016/j.bbamem.2021.183586
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发表时间：
2021-06-01
期刊：
影响因子：
--
通讯作者：
Feigenson GW
中科院分区：
文献类型：
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作者：
Enoki TA;Wu J;Heberle FA;Feigenson GW
质膜（PM）的脂质组成是不对称的。外质和细胞质小叶的独特且特征性的脂质组成导致每个小叶中不同的脂质-脂质相互作用和物理化学性质。外质小叶具有形成共存的有序和无序流体域的内在能力，而细胞质小叶似乎形成单一流体相。为了更好地理解影响域的小叶间相互作用，我们将捕获 PM 显着特性的非对称模型膜与更简单的对称膜进行了比较。使用通过半融合与支持的脂质双层制备的不对称巨型单层囊泡（aGUV），我们研究了表征共存有序+无序结构域行为的结构域线张力。线张力可以与不同相的接触周长相关。与宏观相分离相比，调制相的出现被发现是磁畴线张力下降的有力指标。 1,2-二硬脂酰-sn-甘油-3-磷酸胆碱（DSPC）/ 1,2-二油酰-sn-甘油-3-磷酸胆碱（DOPC）/ 1-棕榈酰-2-油酰-甘油-3-磷酸胆碱（POPC）/胆固醇（chol）的对称GUV通过用GUV外叶替换而形成aGUV DOPC/chol = 0.8/0.2 以创建细胞质传单模型。这些 aGUV 显示外质模型小叶的有序 + 无序域的线张力较低。
The plasma membrane (PM) is asymmetric in lipid composition. The distinct and characteristic lipid compositions of the exoplasmic and cytoplasmic leaflets leads to different lipid-lipid interactions and physical-chemical properties in each leaflet. The exoplasmic leaflet possesses an intrinsic ability to form coexisting ordered and disordered fluid domains, whereas the cytoplasmic leaflet seems to form a single fluid phase. To better understand the interleaflet interactions that influence domains, we compared asymmetric model membranes that capture salient properties of the PM with simpler symmetric membranes. Using asymmetric giant unilamellar vesicles (aGUVs) prepared by hemifusion with a supported lipid bilayer, we investigate the domain line tension that characterizes the behavior of coexisting ordered + disordered domains. The line tension can be related to the contact perimeter of the different phases. Compared to macroscopic phase separation, the appearance of modulated phases was found to be a robust indicator of a decrease in domain line tension. Symmetric GUVs of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)/ 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/ 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC)/cholesterol (chol) were formed into aGUVs by replacing the GUV outer leaflet with DOPC/chol = 0.8/0.2 in order to create a cytoplasmic leaflet model. These aGUVs revealed lower line tension for the ordered + disordered domains of the exoplasmic model leaflet.