Molecular design of amphiphiles with DNA transfer ability into cell

具有季铵盐头、碳氢尾和带有亚甲基基团的谷氨酸连接体的阳离子两亲分子已被用于将DNA输送到真核细胞。我们研究了不同阳离子两亲化合物的DNA转染率与其理化性质的关系1.我们发现，双烷基铵两亲化合物N-[对-(2-三甲基氨乙氧基)苯甲酰基]-L-谷氨酸溴化物的DNA转染率高于市售脂类DOTMA，并且它们的基因转移效率与理化性质之间有很好的相关性.两亲化合物的相变温度(TC)低于培养温度，并形成稳定的小囊泡，是DNA进入培养细胞的良好载体并设计合成了一种活性更高的新型阳离子两亲分子。3.通过电子显微镜、CD和NMR光谱、荧光光谱等手段研究了阳离子两亲分子与DNA的结构相互作用。在间隔区带有苯基的两亲分子通过与DNA结合来限制其流动性，而其他两亲分子则足够灵活地沿DNA螺旋排列。另一方面，DNA的构象被形成双分子层的两亲分子在低于其T_c的温度下强迫改变。

Cationic amphiphiles which have aquaternary ammonium head, hydrocarbon tailsanda glutamic acid connector with methylenespacer have been used for delivery ofDNA into eukaryotic cells. we studied thecorrelation between the efficiency ofvarious cationic amphiphiles in DNA transfection and their physicochemical properties1.We found that one of dialkyl ammonium amphiphile, didodecyl N- [ p- ( 2-trimethylammonioethoxy ) benzoyl ] -L-glutamate bromide, had a higher DNA transfection than commercially available lipid, DOTMA,and that there was a good correlation between their efficiencies in gene transfer and physicochemical characteristics.Amphiphilic compounds tthe phase transition temperatures ( Tc )of which are lower than the culture temperature and which form small stable vesicles are good carriers of DNA into cultured cells.2.The result makes it possible to design compounds with a more efficient DNA transfection ability, and we designed and obtained a new cationic amphiphile with higher activity.3.We investigated interaction the structural between cationic amphiphilesandDNA,bymeans of electron microscopy, CDandNMRspectroscopies, and fluoroscopy. Amphiphiles with phenylene in the spacer regionare restricted their mobility by bindingwith DNA while others are flexibleenough for arranging along DNA helix. Ontheother hand, conformation of DNA is forced to change by bilayr-forming amphiphiles at lower temperature than their Tc's.