CAJ | 학술논문

应用同步辐射低角X射线衍射研究由短链DNA/磷脂在固体表面形成的复合多层膜结构.将DNA/磷脂混合溶液(DOTAP/DOPC混合磷脂,其中Φ_(DOTAP)定义为DOTAP在混合磷脂中的质量百分比)浇铸在经过亲水处理的表面上,在溶剂蒸发过程中自组装形成高度有序的多层膜结构.按DNA骨架上所带负电荷的数目与DOTAP所带正电荷数目相等的比例制备一系列具有不同Φ_(DOTAP)值的样品.实验结果表明,随着DNA含量的增加,多层膜先后出现DNA贫瘠相和DNA富集相.在DNA贫瘠相中,DNA分子被包埋在磷脂分子的亲水头中;而在DNA富集相中,DNA分子紧密排列在磷脂的亲水头层间.并且详细分析了DNA/磷脂多层膜出现DNA贫瘠相和DNA富集相以及产生相变的原因.
응용동보복사저각X사선연사연구유단련DNA/린지재고체표면형성적복합다층막결구.장DNA/린지혼합용액(DOTAP/DOPC혼합린지,기중Φ_(DOTAP)정의위DOTAP재혼합린지중적질량백분비)요주재경과친수처리적표면상,재용제증발과정중자조장형성고도유서적다층막결구.안DNA골가상소대부전하적수목여DOTAP소대정전하수목상등적비례제비일계렬구유불동Φ_(DOTAP)치적양품.실험결과표명,수착DNA함량적증가,다층막선후출현DNA빈척상화DNA부집상.재DNA빈척상중,DNA분자피포매재린지분자적친수두중;이재DNA부집상중,DNA분자긴밀배렬재린지적친수두층간.병차상세분석료DNA/린지다층막출현DNA빈척상화DNA부집상이급산생상변적원인.
Synchrotron radiation X-ray diffraction study was performed on short chain DNA/lipid multilayers prepared by drop-casting solutions of DNA and lipid mixtures onto solid surfaces. DOTAP and DOPC mixtures were used in the study with Φ_(DOTAP) denoting the DOTAP content. The DNA contents are such that the systems are at their isoelectric point. The multilayers are formed via self-assembly during evaporation of the solvent. The results indicate that the short chain DNA molecules are embedded randomly in the hydrophilic headgroup regions of the lipid bilayers when Φ_(DOTAP)≤50%, while the DNA molecules form a closely packaged layer inside each lipid bilayers when Φ(DOTAP)≥90%. The DNA-poor phase and DNA-rich phase coexist at intermediate DNA contents. The bilayers are distorted in the DNA-poor phase, while they are well-ordered in the DNA-rich phase. The phase transition is driven by the lowering of the interfacial energy.