Dynamics and size of crosslinking-induced lipid nanodomains in model membranes
2012 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 102, no 3, 294a- p.Article in journal, Meeting abstract (Refereed) Published
Changes of membrane organization upon crosslinking of its components trigger cellsignaling response to various exogenous factors. Crosslinking of raft gangliosides GM1with cholera toxin (CTxB) was demonstrated to cause microscopic phase separation inmodel membranes and the CTxB-GM1 complexes forming a minimal lipid raft unit aresubject of ongoing cell membrane research. Yet, those subdiffraction sized rafts havenever been described in terms of size and dynamics. By means of two-color z-scanfluorescence correlation spectroscopy, we show that the nano-sized domains are formedin model membranes at lower sphingomyelin content than needed for the large scalephase separation and that the CTxB-GM1 complexes are confined in the domains poorlystabilized with sphingomyelin. Fluorescence resonance energy transfer together withMonte Carlo modeling of the donor decay response reveal the domain radius ofapproximately 8 nm, which increases at higher sphingomyelin content. We observed twotypes of differently behaving domains, which suggests a dual role of the crosslinker: first,local transient condensation of the GM1 molecules compensating lack of sphingomyelinand second, coalescence of existing nanodomains ending in large scale phase separation.
Place, publisher, year, edition, pages
2012. Vol. 102, no 3, 294a- p.
IdentifiersURN: urn:nbn:se:umu:diva-52464DOI: 10.1016/j.bpj.2011.11.1628OAI: oai:DiVA.org:umu-52464DiVA: diva2:504860
Kompletteras 2012-092012-02-222012-02-222012-09-27Bibliographically approved