title: Observation of the three-dimensional structure of actin bundles formed with polycations.
abstract: Three-dimensional structures of actin bundles formed with polycations were observed by using transmission electron microtomography and atomic force microscopy. We found, for the first time, that the cross-sectional morphology of actin bundles depends on the polycation species and ionic strength, while it is insensitive to the degree of polymerization and concentration of polycation. Actin bundles formed with poly-N-[3-(dimethylamino)propyl] acrylamide methyl chloride quaternary show a ribbon-like cross-sectional morphology in low salt concentrations that changes to cylindrical cross-sectional morphology with hexagonal packing of the actin filaments in high salt concentrations. Contrastingly, actin bundles formed with poly-L-lysine show triangular cross-sectional morphology with hexagonal packing of the actin filaments. These variations in cross-sectional morphology are discussed in terms of anisotropy in the electrostatic energy barrier.
authors.affiliation: Department of Biological Science, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shikinaka
authors.forename: Hyuckjoon
authors.initials: H
authors.lastname: Kwon
authors.forename: Akira
authors.initials: A
authors.lastname: Kakugo
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Furukawa
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Osada
authors.forename: Jian Ping
authors.initials: JP
authors.lastname: Gong
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Aoyama
authors.forename: Hideo
authors.initials: H
authors.lastname: Nishioka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Jinnai
authors.forename: Takaharu
authors.initials: T
authors.lastname: Okajima
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry; D000199:Actins / Q000032:analysis / Q000737:chemistry*; D000818:Animals; D021621:Imaging, Three-Dimensional / Q000379:methods; D015394:Molecular Structure; D049897:Pectinidae; D011073:Polyamines / Q000032:analysis / Q000737:chemistry*; D000071228:Polyelectrolytes
chemical_list: D000199:Actins; D011073:Polyamines; D000071228:Polyelectrolytes