Langmuir-Blodgett膜超分子SM/DOPC/Chol三元脂系的原子力显微镜观察

用原子力显微镜研究了胆固醇(Chol)对鞘磷脂(SM)/1,2-二油酸甘油-3-磷脂酰胆碱(DOPC)二元脂系统结构的影响和神经酰胺对SM/DOPC/Chol三元脂系统结构的影响. 实验发现, 在SM/DOPC二元脂系统中, 胆固醇和带饱和脂肪酸链的磷脂发生相互作用形成微区结构, 随着胆固醇含量的增加, 微区的面积逐渐增大, 形成了稳定的片层结构. 当把神经酰胺加入到等摩尔配比的SM/DOPC/Chol三元脂系统中时, 随着神经酰胺比例的增加, 先形成紧密的聚集态结构, 然后逐渐演变成具有特定微区的网状结构. 研究结果表明, 微区的形成主要是由分子不同的官能团之间的相互作用所决定, 这可能在细胞信号传导等生理活动中起到重要的作用.

Atomic Force Microscopic Observation on the Supramolecular Structure of Langmuir-Blodgett Films in the SM/DOPC/Chol Ternary System

Atomic force microscopy has been used to study the effect of cholesterol(Chol)on the structure of equimolar sphingomyelin(SM)/1,2-dioleoy-sn-glycero-3-phosphocholine(DOPC)binary bilayers and ceramide on the structure of SM/DOPC/cholesterol ternary bilayers.We found that the formation of micro-domain structure in the binary lipid system was attributed to the interaction between cholesterol and SM with saturated lipid chain.As the contents of cholesterol increasing,the microdomain structure gradually expanded and formed a stable lamellar structure.When adding ceramide to equimolar SM/DOPC/Chol ter-nary system,as the proportion of ceramide increasing,a close aggregate structure appeared at first,and then developed to a network structure with particular microdomain.The results showed that the formations of microdomains were mainly due to the interaction of different functional groups,which belonged to individ-ual molecule.These microdomains may play important roles in cellular signaling.