Macroscopic consequences of the action of phospholipase C on giant unilamellar liposomes.
Macroscopic consequences of the action of phospholipase C on giant unilamellar liposomes.
复制标题
磷脂酶 C 对巨型单层脂质体作用的宏观后果。
DOI：
10.1016/s0006-3495(02)75219-3
复制
发表时间：
2002
影响因子：
3.4
通讯作者：
P. Kinnunen
中科院分区：
文献类型：
--
作者：
J. Holopainen;M. Angelova;T. Söderlund;P. Kinnunen
通过相差显微镜和荧光显微镜研究了巨型 1-硬脂酰-2-油酰-sn-甘油-3-磷酸胆碱 (SOPC) 单层囊泡（GUV，直径 10-100μm）中磷脂酶 C (PC-PLC) 形成二酰甘油的宏观后果。 PC-PLC 导致流体 SOPC GUV 发生一系列快速逐步收缩，一直持续到囊泡消失超出显微镜的光学分辨率。 GUV 中 N-棕榈酰基鞘磷脂（摩尔分数 X=0.25）的存在不会影响 PC-PLC 反应的结果。除了水解之外，PC-PLC 还诱导邻近囊泡的粘附。当使用多层 SOPC 囊泡时，其直径仅轻微减小，这表明 PC-PLC 只能在外单层中发挥其水解活性。 1,2-二肉豆蔻酰-sn-甘油-3-磷酸胆碱 (DMPC) GUV 在高于其主要相变温度 Tm 时，即当双层处于液晶状态时，也观察到一系列逐步收缩。然而，在低于 Tm 的凝胶态 DMPC GUV 中没有观察到这一过程。这些结果得到了 PC-PLC 在超过 DMPC 大单层囊泡（直径~0.1μm）用作底物的 Tm 时增强的活性的支持。对 SOPC 单层的研究表明，PC-PLC 仅在表面压力低于 ∼30mN/m 时才能发挥其水解活性。因此，凝胶态 DMPC GUV 没有变化可以通过这些囊泡中的平衡侧压超过该临界值来解释。
Macroscopic consequences of the formation of diacylglycerol by phospholipase C (PC-PLC) in giant 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) unilamellar vesicles (GUVs, diameter 10–100μm) were studied by phase contrast and fluorescence microscopy. PC-PLC caused a series of fast stepwise shrinkages of fluid SOPC GUVs, continuing until the vesicle disappeared beyond the optical resolution of the microscope. The presence ofN-palmitoyl-sphingomyelin (mole fractionX=0.25) in the GUVs did not affect the outcome of the PC-PLC reaction. In addition to hydrolysis, PC-PLC induced adhesion of vicinal vesicles. When multilamellar SOPC vesicles were used only a minor decrease in their diameter was evident suggesting that PC-PLC can exert its hydrolytic activity only in the outer monolayer. A series of stepwise shrinkages was observed also for 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) GUVs above their main phase transition temperature,Tm, i.e., when the bilayer is in the liquid crystalline state. However, this process was not observed for DMPC GUVs in the gel state, belowTm. These results are supported by the enhanced activity of PC-PLC upon exceedingTmof DMPC large unilamellar vesicles (diameter ∼0.1μm) used as a substrate. Studies on SOPC monolayers revealed that PC-PLC can exert its hydrolytic activity only at surface pressures below ∼30mN/m. Accordingly, the lack of changes in the gel state DMPC GUVs could be explained by the equilibrium lateral pressure in these vesicles exceeding this critical value.
影响因子：
6.8
作者：
Brockman, H
通讯作者：
Brockman, H
短链卵磷脂/长链磷脂单层囊泡的酶水解：磷脂酶对基质相状态的敏感性。
影响因子：
2.9
作者：
Gabriel,NE;Agman,NV;Roberts,MF
通讯作者：
Roberts,MF