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  

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

作　　者：莫春丽[1] DICKO Cedric 邵正中[1] 陈新[1] 

机构地区：[1]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 [2]牛津大学动物学系

出　　处：《化学学报》2009年第22期2641-2644,共4页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20525414);科技部863计划(No.2006AA03Z452);教育部长江学者和创新团队发展计划资助项目

摘　　要：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.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 dom：inating 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.

关 键 词：蚕丝蛋白 酸碱度 扩散 Β-折叠 动态跟踪 

分 类 号：O629.73[理学—有机化学] O657.33[理学—化学]