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包裹在脂质体中胰岛素的二级结构

张煙, 黄力新, 聂松青, 齐宪荣, 张强*   

  1. 1.北京大学药学院药剂学系;
    2.北京基础医学院生物物理系, 北京 100083
  • 收稿日期:2002-11-26 修回日期:2003-02-10 出版日期:2003-03-15 发布日期:2003-03-15
  • 通讯作者: 张强*

FTIR Characterization of the Secondary Structure of Insulin Encapsulated within Liposome

ZHANG Xuan, HUANG Li-xin, NIE Song-qing, QI Xian-rong, ZHANG Qiang*   

  1. 1.Department of Pharmaceutics, School of Pharmaceutical sciences;
    2.Department of Biophysics, School of Basical Medical Sciences, Peking University, Beijing 100083, China
  • Received:2002-11-26 Revised:2003-02-10 Online:2003-03-15 Published:2003-03-15
  • Contact: ZHANG Qiang*

摘要: 目的 以单纯胰岛素为对照, 采用傅立叶红外转换光谱(Fourier Transform Infrared FTIR)研究包裹在脂质体内部胰岛素二级结构的变化. 方法 分别对单纯胰岛素、胰岛素与空白脂质体混合物(样品I)及包裹胰岛素的脂质体(样品II)样品进行FTIR测定. 结果 与单纯胰岛素相比, 样品III与胰岛素的FTR谱图形状基本一致, 仅其中的α-螺旋略有下降(36%分别到32%31%), β-折叠略有增加(48%分别到53%51%).样品I同样品II相比, 胰岛素的二级结构无明显差别(α-螺旋分别为32%31%, β-折叠分别为53%51%).说明包裹在脂质体内的胰岛素未与脂质体的膜发生插膜作用, 所产生与单纯胰岛素二级结构之间微小差别的原因是由于部分胰岛素铺展在脂质体膜表面所致的. 结论 FTIR测定被载体包裹的蛋白多肽药物的二级结构, 具有快速直接和非破坏性的特点.FTIR测定, 包裹在脂质体内的胰岛素与单纯胰岛素的二级结构相比无明显的变化, 仍保持原胰岛素的二级结构.

关键词: 傅立叶红外光谱, 胰岛素, 脂质体, 二级结构

Abstract: Aim To determine the secondary structure of insulin encapsulated within liposome. Methods The secondary structure of native insulin, mixture of insulin with liposome (sample I) and insulin encapsulated within liposome (sample II) were determined by FTIR (Fourier Transform Infrared) spectroscopy. Results The secondary structure of insulin encapsulated within liposome (II) are similar with the secondary structure of native insulin. The difference existed in the amount of α-helices (from 36% of insulin to 31% of sample II) and β-sheet (from 48% of insulin to 51% of sample II). The content of α-helices and β-sheet of insulin in sample I was found to be very close to that of sample II. The results revealed that the insulin encapsulated within liposome possibly spread on the surface of liposome, without inserting into the liposome membrane. Conclusion The secondary structure of insulin encapsulated within liposome is similar with the native insulin.

Key words: FTIR, FTIR, insulin, insulin, liposome, liposome, secondary structure, secondary structure

中图分类号: 

Supporting: Foundation item: National Science Fund project, 29992590-7.
*Corresponding author. Tel.: 86-010-62092791