化学学报 ›› 2012, Vol. 70 ›› Issue (05): 667-673 .DOI: 10.6023/A1106233 上一篇    

研究论文

乌苏酸/DPPC 混合单层膜相互作用的研究

王夫雨, 孙润广, 陈莹莹, 王小梅, 柴政   

  1. 陕西师范大学 物理学与信息技术学院生物物理与生物医学工程研究室 西安 710062
  • 投稿日期:2011-06-23 修回日期:2011-10-17 发布日期:2011-11-22
  • 通讯作者: 孙润广 E-mail:sunrunguang@snnu.edu.cn
  • 基金资助:

    国家自然科学基金(No. 20772077)和教育部高等学校博士学科点专项科研基金(No. 200807180001)资助项目.

Monolayer Study on the Interaction between Ursolic Acid and DPPC

Wang Fuyu, Sun Runguang, Chen Yingying, Wang Xiaomei, Chai Zheng   

  1. Laboratory of Biophysics and Biomedical Engineering, College of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062
  • Received:2011-06-23 Revised:2011-10-17 Published:2011-11-22
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 20772077) and Doctoral Fund of Ministry of Education of China (No. 200807180001).

乌苏酸(UA)为五环三萜羧基酸类化合物, 是一种中药有效成分. 它进入细胞的过程与膜脂分子有密切关系. 选用生物膜系统中的膜脂分子二棕榈酰基磷脂酰胆碱(DPPC)为代表, 通过LB(Langmuir-Blodgett)膜技术获得乌苏酸与DPPC 混合单层膜的表面压力/平均分子面积(π-A)曲线. 分析了混合单层膜的平均和过量分子面积、弹性系数等热力学参量, 并用原子力显微镜进行了研究. 比较了乌苏酸/DPPC 与胆固醇/DPPC 混合单层膜的异同. 实验结果表明: 乌苏酸能促使DPPC 的凝聚; 乌苏酸/DPPC 两组分的物质的量比与混合单层膜的膜压对单层膜的压缩性、稳定性和热力学特性有影响, 对单层膜中不同组分间的混合性以及分子间的相互作用具有重要的影响.

关键词: 乌苏酸, 单层膜, 弹性模量, 过量吉布斯自由能, 原子力显微镜

In this work, the interaction of urasolic acid (UA, a natural pentacyclic triterpene) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC, an important phospholipid in cell membrane) was investigated. The mean and excess surface area per molecule, elastic modulus, excess Gibbs energy, and interaction parameter of mixed monolayer were studied based on the surface pressure-area isotherms. The authors found that, as well as cholesterol, UA can induce the DPPC molecules on the monolayer condensation. The stability, compressibility and thermodynamic characteristics of binary system of UA and DPPC are connected with the surface pressure and the mole faction of UA. The AFM experiment supported the conclusion effectively.

Key words: urasolic acid, monolayer, elastic modulus, excess Gibbs energy, atomic force microscopy