Wang C Y, Hughes K W, Huang L
Department of Biochemistry, University of Tennessee, Knoxville, Tennessee 37996-0840.
Plant Physiol. 1986 Sep;82(1):179-84. doi: 10.1104/pp.82.1.179.
We demonstrated that the liposomes composed of dioleolylphosphatidylethanolamine/cholesterol/oleic acid (4:4:2) dramatically release their contents at a pH of less than or equal to 6.0 and are capable of delivering their contents into the cytoplasm of higher plant protoplasts. This is shown by using a soluble fluorescent dye, calcein, as a liposome-entrapped marker. We found that calcein fluorescence was evenly distributed in the cytoplasm of wild carrot protoplasts after the incubation of protoplasts with liposomes in the presence of polyethylene glycol 6000. At 0.45 micro mole phospholipid per 6 x 10(5) protoplast, for example, the percentage of protoplasts which took up liposomes was 89% which was much higher than that achieved by conventional pH-insensitive liposomes. In this study, liposomes were prepared by a detergent dialysis method which avoided sonication and organic solvents. Thus macromolecules such as proteins and nucleic acids could be entrapped in the liposomes and delivered to the cytoplasm of the protoplasts.
我们证明，由二油酰磷脂酰乙醇胺/胆固醇/油酸（4:4:2）组成的脂质体在pH值小于或等于6.0时会显著释放其内容物，并且能够将其内容物递送至高等植物原生质体的细胞质中。这是通过使用一种可溶性荧光染料钙黄绿素作为脂质体包裹的标记物来证明的。我们发现，在聚乙二醇6000存在的情况下，将原生质体与脂质体孵育后，钙黄绿素荧光在野生胡萝卜原生质体的细胞质中均匀分布。例如，在每6×10⁵个原生质体中含有0.45微摩尔磷脂时，摄取脂质体的原生质体百分比为89%，这远高于传统的对pH不敏感的脂质体所达到的比例。在本研究中，脂质体通过去污剂透析法制备，避免了超声处理和有机溶剂。因此，蛋白质和核酸等大分子可以被包裹在脂质体中并递送至原生质体的细胞质中。
