title: Intermittent contact mode AFM investigation of native plasma membrane of Xenopus laevis oocyte.
abstract: Intermittent contact mode atomic force microscopy (AFM) was used to visualize the native plasma membrane of Xenopus laevis oocytes. Oocyte membranes were purified via ultracentrifugation on a sucrose gradient and adsorbed on mica leaves. AFM topographs and the corresponding phase images allowed for visualization and identification of both oocyte plasma membrane patches and pure lipid bilayer regions with a height of about 5 nm within membrane patches. The quantitative analysis showed a normal distribution for the lateral dimension and height of the protein complexes centered on 16.7 +/- 0.2 nm (mean +/- SE, n = 263) and 5.4 +/- 0.1 nm (n = 262), respectively. The phase signal, providing material-dependent information, allowed for the recognition of structural features observed in AFM topographs.
authors.affiliation: Giovanni Esposito Institute of General Physiology and Biological Chemistry, University of Milan, Via Trentacoste 2, 20134, Milan, Italy. francesco.orsini@unimi.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Orsini
authors.forename: M
authors.initials: M
authors.lastname: Santacroce
authors.forename: P
authors.initials: P
authors.lastname: Arosio
authors.forename: M
authors.initials: M
authors.lastname: Castagna
authors.forename: C
authors.initials: C
authors.lastname: Lenardi
authors.forename: G
authors.initials: G
authors.lastname: Poletti
authors.forename: F V
authors.initials: FV
authors.lastname: Sacchi
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D018360:Crystallography, X-Ray; D005260:Female; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D018625:Microscopy, Atomic Force; D009865:Oocytes / Q000166:cytology*; D013395:Sucrose / Q000737:chemistry; D013997:Time Factors; D014461:Ultracentrifugation; D014982:Xenopus laevis
chemical_list: D000538:Aluminum Silicates; D008051:Lipid Bilayers; D008565:Membrane Proteins; D013395:Sucrose; C011934:mica