Breisblatt W, Ohki S
J Membr Biol. 1976 Oct 20;29(1-2):127-46. doi: 10.1007/BF01868956.
Effect of cholesterol, divalent ions and pH on spherical bilayer membrane fusion was studied as a function of increasing temperature. Spherical bilayer membranes were composed of natural [phosphatidylcholine (PC) and phosphatidylserine (PS)] as well as synthetic (dipalmitoyl-PC, dimyristoyl-PC and dioleoyl-PC) phospholipids. Incorporation of cholesterol into the membrane (33% by weight) suppressed the fusion temperature and also greatly reduced the percentage of membrane fusion. The presence of 1 mM divalent ions (Ca++, Mg++ or Mn++) on both sides or one side of the PC membrane did not affect appreciably its fusion characteristic with temperature, but the PS membrane fusion with temperature was greatly enhanced by the presence of divalent ions. The variation of pH of the environmental solution in the range of 5.5 approximately 7.0 did not affect the membrane fusion characteristic. However, at pH 8.5, the fusion with respect to temperature was shifted toward the lower temperature by approximately 3degreesC for PC and PS membranes, and at pH 3.0 the opposite situation was observed as the fusion temperature was increased by 6degreesC for PS membranes and by 4degreesC for PC membranes The results seem to indicate that membrane fluidity and structural instability in the bilayer are important for membrane fusion to occur.
研究了胆固醇、二价离子和pH值对球形双层膜融合的影响，并将其作为温度升高的函数进行研究。球形双层膜由天然磷脂（磷脂酰胆碱（PC）和磷脂酰丝氨酸（PS））以及合成磷脂（二棕榈酰磷脂酰胆碱、二肉豆蔻酰磷脂酰胆碱和二油酰磷脂酰胆碱）组成。将胆固醇掺入膜中（重量比为33%）会抑制融合温度，并大大降低膜融合的百分比。在PC膜的两侧或一侧存在1 mM二价离子（Ca++、Mg++或Mn++），对其与温度相关的融合特性没有明显影响，但二价离子的存在会大大增强PS膜与温度相关的融合。环境溶液的pH值在5.5至7.0范围内变化时，不会影响膜融合特性。然而，在pH 8.5时，PC膜和PS膜与温度相关的融合向较低温度方向移动了约3℃，而在pH 3.0时，观察到相反的情况，因为PS膜的融合温度升高了6℃，PC膜的融合温度升高了4℃。结果似乎表明，双层膜中的膜流动性和结构不稳定性对于膜融合的发生很重要。
