化学学报 ›› 2009, Vol. 67 ›› Issue (22): 2641-2644. 上一篇    

研究论文

时间分辨全反射红外光谱对醋酸诱导丝蛋白构象转变的研究

莫春丽a,DICKO Cedricb,邵正中*,a,陈新a   

  1. (a教育部聚合物分子工程重点实验室 复旦大学高分子科学系和先进材料实验室 上海 200433) (b牛津大学动物学系 牛津 OX3 3PS 英国)
  • 投稿日期:2009-04-27 修回日期:2009-05-21 发布日期:2009-07-08
  • 通讯作者: 邵正中 E-mail:zzshao@fudan.edu.cn
  • 基金资助:

    国家自然科学基金(No.20525414);科技部863计划(No.2006AA03Z452)

Time-Resolved Total Reflectance FT-IR Spectroscopy Characterization on Conformational Change of Silk Fibroin Induced by Acetic Acid

Mo, Chunlia,Dicko, Cedricb,Shao, Zhengzhong*,a,Chen, Xina   

  1. (a Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Advanced Materials Laboratory, Department of Macromolecular Science, Fudan University, Shanghai 200433) (b Oxford University, Zoology Department, South Parks Road, OX1 3PS, UK)
  • Received:2009-04-27 Revised:2009-05-21 Published:2009-07-08

采用时间分辨全反射红外光谱为主要分析手段, 对醋酸在丝蛋白膜中的扩散过程及其对丝蛋白构象转变机理进行了研究. 结果表明, 醋酸能够诱导丝蛋白构象转变为β-折叠. 醋酸的扩散速率和β-折叠构象的生成速率较为相似, 表明醋酸分子渗透到丝蛋白聚集体中是破坏丝蛋白原有氢键并诱导肽链重排, 进而实现构象转变的一个先决条件. 同时, 通过比较真空干燥处理前后丝蛋白膜的实验结果, 证实了丝蛋白中的水含量是影响醋酸的扩散速度以及丝蛋白多肽链重排速度的一个重要因素.

关键词: 蚕丝蛋白, 酸碱度, 扩散, b-折叠, 动态跟踪

It has been proved that time-resolved total reflectance FT-IR spectroscopy is a useful tool for investigating acetic acid diffusion in silk fibroin film and conformational transition of silk fibroin. Acetic acid could induce the construction of highly dominating content of β-sheet conformation in the silk fibroin film, in addition, the kinetic curve of organic solvent diffusion was similar to that of conformational transition as both processes reached equilibria at the same time. The access of acetic acid into the silk fibroin architecture appeared to be a necessary step in which the organic solvent could interact with silk protein, breaking its original hydrogen bond and inducing re-alignment of peptide chains. Furthermore, the content of water appeared to be an important factor in this dynamic system.

Key words: silk fibroin, acidity-basicity, diffusion, β-sheet, dynamic process