近日,中國科學院合肥物質科學研究院強磁場科學中心副研究員鄭基深在清華大學教授劉磊和強磁場科學中心研究員田長麟共同指導下發展了膜蛋白化學全合成新方法,合成了全長流感病毒通道蛋白M2及內向整流鉀離子通道蛋白Kir5.1膜嵌入結構域,並和強磁場中心的博士生餘木合作,應用單分子通道檢測方法實現了化學全合成的跨膜通道蛋白的功能檢測。該項研究成功展示了應用化學方法全合成具有生理功能的離子通道膜蛋白的最新研究進展。
離子通道蛋白能調節細胞內外離子平衡並產生細胞膜動作電位,是在病毒侵染、神經系統、心血管系統、生殖系統等生理活動中起著關鍵作用的一類膜蛋白。有關離子通道的核磁共振研究不僅需要較純的膜蛋白、還需要在合適的位點進行同位素標記。劉磊研究組和田長麟研究組合作發展和應用Fmoc化學新方法實現了毫克級離子通道蛋白的合成,並成功應用單分子通道方法鑑定了化學全合成的離子通道的功能。化學合成的膜蛋白將為生物化學和生物物理學研究提供其他方法難以獲得的實驗材料。
相關研究成果已經以《通過Fmoc化學實現中小分子量膜蛋白的全合成》為題在線發表在《美國化學學會志》雜誌上(Expedient Total Synthesis of Small to Medium-Sized Membrane Proteins via Fmoc Chemistry, Journal of the American Chemical Society)。
餘木除了在化學全合成的離子通道單分子檢測方面作出貢獻外,還在建立單分子通道檢測實驗平臺時優化了細菌外膜蛋白G(OmpG)的通道特性,該研究結果將有助於進一步發展基於OmpG的單分子檢測器件。相關工作以《外膜蛋白G的關鍵pH門控殘基突變增加其在平面脂雙層中的開放概率》為題發表在Protein & Cell雜誌上。(Mutation of the critical pH-gating residues histidine 231 to glutamate increase open probability of outer membrane protein G in planar lipid bilayer)(生物谷Bioon.com)
生物谷推薦的英文摘要
Journal of The American Chemical Society DOI: 10.1021/ja500222u
Expedient Total Synthesis of Small to Medium-Sized Membrane Proteins via Fmoc Chemistry
Ji-Shen Zheng , Mu Yu , Yun-Kun Qi , Shan Tang , Fei Shen , Zhi-Peng Wang , Liang Xiao , Longhua Zhang , Chang-Lin Tian *, and Lei Liu *
Total chemical synthesis provides a unique approach for the access to uncontaminated, monodisperse, and more importantly, post-translationally modified membrane proteins. In the present study we report a practical procedure for expedient and cost-effective synthesis of small to medium-sized membrane proteins in multimilligram scale through the use of automated Fmoc chemistry. The key finding of our study is that after the attachment of a removable arginine-tagged backbone modification group, the membrane protein segments behave almost the same as ordinary water-soluble peptides in terms of Fmoc solid-phase synthesis, ligation, purification, and mass spectrometry characterization. The efficiency and practicality of the new method is demonstrated by the successful preparation of Ser64-phosphorylated M2 proton channel from influenza A virus and the membrane-embedded domain of an inward rectifier K+ channel protein Kir5.1. Functional characterizations of these chemically synthesized membrane proteins indicate that they provide useful and otherwise-difficult-to-access materials for biochemistry and biophysics studies.