title: Atomic force microscopy of asymmetric membranes from turtle erythrocytes.
abstract: The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China ; University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
authors.forename: Mingjun
authors.initials: M
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
authors.forename: Haijiao
authors.initials: H
authors.lastname: Xu
authors.affiliation: School of physics, Northeast Normal University, Changchun, Jilin 130024, P.R. China.
authors.forename: Bohua
authors.initials: B
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
authors.forename: Xian
authors.initials: X
authors.lastname: Hao
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
authors.forename: Junguang
authors.initials: J
authors.lastname: Jiang
authors.affiliation: School of physics, Northeast Normal University, Changchun, Jilin 130024, P.R. China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
authors.forename: Hongda
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002645:Chickens; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000648:ultrastructure*; D005399:Fishes; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008961:Models, Structural; D014426:Turtles / Q000502:physiology*
chemical_list: D008565:Membrane Proteins
keywords: asymmetry; atomic force microscopy; membrane structure; turtle erythrocyte