On the organization of self-assembled actin networks in giant vesicles |
| |
Authors: | L Limozin M Bärmann E Sackmann |
| |
Institution: | Lehrstuhl für Biophysik E22, Physik Department, Technische Universit?t München, James Franck Str., 85748 Garching, Germany-1, DE
|
| |
Abstract: | We studied the formation of actin scaffolds in giant vesicles of dimyristoylphosphatidylcholine (DMPC). Polymerization of
actin was induced at low ionic strength through ionophore-mediated influx of Mg2+ (2 mM). The spatial organization of the filamentous actin was visualized by confocal and epifluorescence microscopy as a
function of the filaments length and membrane composition, by including various amounts of cholesterol or lipids with neutral
and positively charged polyethyleneglycol headgroups (PEG lipopolymers). In vesicles of pure DMPC, the newly polymerized actin
adsorbs to the membrane and forms a thin shell. In the presence of 2.5 mol% lipopolymers or of cholesterol at a molar fraction
x = 0.37, formation of a thin adsorbed film is impeded. A fuzzy cortex is predominantly formed in vesicles of diameter d smaller than the filament persistence length ( d ⩽ 15μm) while for larger vesicles a homogeneous network formation is favoured in the bulk of the vesicle. The fuzzy-cortex
formation is interpreted as a consequence of the reduction of the bending energy if the actin filaments accumulate close to
the vesicle wall.
Received: 17 January 2002 / Accepted: 21 March 2003 / Published online: 24 April 2003
RID="a"
ID="a"e-mail: Laurent_Limozin@ph.tum.de |
| |
Keywords: | PACS 87 16 Dg Membranes bilayers and vesicles – 87 16 Ka Filaments microtubules their networks and supramolecular assemblies |
本文献已被 PubMed SpringerLink 等数据库收录! |
|