Subtraction of liposome signals in cryo-EM structural determination of protein-liposome complexes  

作　　者：李首卿 李明 王玉梅 李雪明 Shouqing Li;Ming Li;Yumei Wang;Xueming Li(Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory for Protein Sciences of Ministry of Education,School of Life Sciences,Tsinghua University,Beijing 100084,China;State Key Laboratory of Membrane Biology,School of Life Sciences,Tsinghua University,Beijing 100084,China;Tsinghua–Peking Joint Center for Life Sciences,Beijing 100084,China;Beijing Frontier Research Center for Biological Structure,Beijing 100084,China;School of Life Sciences,Tsinghua University,Beijing 100084,China;Beijing Branch of Songshan Lake Materials Laboratory,Beijing 100190,China)

机构地区：[1]Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory for Protein Sciences of Ministry of Education,School of Life Sciences,Tsinghua University,Beijing 100084,China [4]State Key Laboratory of Membrane Biology,School of Life Sciences,Tsinghua University,Beijing 100084,China [5]Tsinghua–Peking Joint Center for Life Sciences,Beijing 100084,China [6]Beijing Frontier Research Center for Biological Structure,Beijing 100084,China [7]School of Life Sciences,Tsinghua University,Beijing 100084,China [8]Beijing Branch of Songshan Lake Materials Laboratory,Beijing 100190,China

出　　处：《Chinese Physics B》2024年第8期569-577,共9页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos.32241023 and 92254306);the Fund from the Tsinghua–Peking Joint Center for Life Sciences;Beijing Frontier Research Center for Biological Structure。

摘　　要：Reconstituting membrane proteins in liposomes and determining their structure is a common method for determining membrane protein structures using single-particle cryo-electron microscopy(cryo-EM).However,the strong signal of liposomes under cryo-EM imaging conditions often interferes with the structural determination of the embedded membrane proteins.Here,we propose a liposome signal subtraction method based on single-particle two-dimensional(2D)classification average images,aimed at enhancing the reconstruction resolution of membrane proteins.We analyzed the signal distribution characteristics of liposomes and proteins within the 2D classification average images of protein–liposome complexes in the frequency domain.Based on this analysis,we designed a method to subtract the liposome signals from the original particle images.After the subtraction,the accuracy of single-particle three-dimensional(3D)alignment was improved,enhancing the resolution of the final 3D reconstruction.We demonstrated this method using a PIEZO1-proteoliposome dataset by improving the resolution of the PIEZO1 protein.

关 键 词：CRYO-EM protein–liposome complexes liposome signal subtraction 2D classification averaging 

分 类 号：Q51[生物学—生物化学] TN16[电子电信—物理电子学]