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Atomic force microscopy imaging of Xenopus laevis oocyte plasma membrane purified by ultracentrifugation
Author(s) -
Santacroce Massimo,
Orsini Francesco,
Mari Stefania Anna,
Mari Massimo,
Lenardi Cristina,
Bettè Sara,
Sacchi Vellea Franca,
Poletti Giulio
Publication year - 2008
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.20559
Subject(s) - xenopus , chemistry , atomic force microscopy , mica , membrane , crystallography , analytical chemistry (journal) , lipid bilayer , biophysics , nanotechnology , chromatography , materials science , biochemistry , biology , composite material , gene
Atomic force microscopy (AFM) was used to investigate the native plasma membrane of Xenopus laevis ( X. laevis ) oocyte purified by means of ultracentrifugation on sucrose gradient and subsequently adsorbed on mica leaves through a physisorption process. Reproducible AFM topography images were collected, analyzed, and compared. AFM images showed the presence of large single or double bilayer membrane sheets covered with protein complexes. The lateral dimension and height of protein complexes imaged in air showed a normal distribution centred on 15.4 ± 0.4 nm (mean ± SE; n = 59) and 3.9 ± 0.2 nm (mean ± SE; n = 57), respectively. A density of about 270 protein complexes per square micron was calculated. Less frequently, ordered nanometer domains with densely packed protein complexes arranged in hexagonal patterns were also visualized in AFM images, confirming previously published data. Their lateral dimension and height showed a normal distribution centred on 23.0 ± 0.4 nm (mean ± SE; n = 42) and 1.5 ± 0.6 nm (mean ± SE; n = 90), respectively. A density of about 870 protein complexes per square micrometer was calculated. Advantages and drawbacks of this new sample preparation for AFM imaging are discussed. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.