Membrane protein transfer from intact cell to liposome

从完整的细胞中充分提取固有的膜蛋白，并对其进行不变性、不失活的重构，是研究膜蛋白功能的基本要求。为此，人工细胞脂质体在基础研究和应用方面都是一种理想的、有前途的工具。为了提高膜蛋白重组脂质体的效率，我们开发了一种新型的人工边界脂质，1,2-二肉豆浆酰基酰胺-1,2-脱氧-磷脂酰胆碱（DDPC），其烷基链由酰胺键连接。当含ddpc的脂质体与红细胞、血小板和肿瘤细胞等完整细胞共孵育时，几种膜蛋白能够有效地从完整细胞转移到脂质体中。此外，利用该技术，我们成功地开发了针对BALB RVD白血病细胞的脂质体疫苗，将肿瘤表面抗原蛋白（TSAP）从肿瘤细胞转移到脂质体中。

Perfect extraction of intrinsic membrane proteins from intact cells and reconstitution of them without any denaturation and deactivation are basic requirement in investigation of the function of membrane proteins. For this purpose, artificial cell liposome seem to be a desirable and promising tool in both basic investigation and application. In order to improve the reconstitution efficiency of membrane proteins into liposomes, we have developed a novel artificial boundary lipid, 1,2-dimyristoylamido-1,2-deoxy- phosphatidylcholine (DDPC), of which alkyl chains are linked by an amide bond. When DDPC-containing liposomes were coincubated with intact cells such as erythrocyte, platelet and tumor cell, several membrane proteins were able to be effectively transferred from the intact cell to the liposome. Using this technique, furthermore, we succeeded in development of liposomal vaccine against BALB RVD leukemia cell for tumor surface antigenic proteins (TSAP) transferred from the tumor cells to liposomes.