The Important Roles of Water in Protein Folding:an Approach by Single Molecule Force Spectroscopy  

作　　者：Bo Cheng Shu-Xun Cui Bo Cheng;Shu-Xun Cui(School of Mechanical Engineering,North University of China,Taiyuan 030051,China;Key Lab of Advanced Technologies of Materials,Ministry of Education of China,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]School of Mechanical Engineering,North University of China,Taiyuan 030051,China [2]Key Lab of Advanced Technologies of Materials,Ministry of Education of China,Southwest Jiaotong University,Chengdu 610031,China

出　　处：《Chinese Journal of Polymer Science》2018年第3期379-384,共6页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21574106 and 21604074);the Sichuan Province Youth Science and Technology Innovation Team(Nos.2016TD0026 and 2017JQ0009)

摘　　要：The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force spectroscopy （SMFS）. The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments. Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded （I27）s chain upon stretching in aqueous solution, which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein. Through the analysis of the free energy changes involved in protein folding, we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions. We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution.The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force spectroscopy （SMFS）. The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments. Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded （I27）s chain upon stretching in aqueous solution, which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein. Through the analysis of the free energy changes involved in protein folding, we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions. We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution.

关 键 词：SMFS PROTEIN FOLDING WATER 

分 类 号：O629.73[理学—有机化学]