Please use this identifier to cite or link to this item: http://dx.doi.org/10.25673/111051
Title: Vesicle budding caused by lysolipid-induced asymmetry stress
Author(s): Hua, Lisa
Kaiser, Michael
Carabadjac, Iulia
Meister, AnnetteLook up in the Integrated Authority File of the German National Library
Hauser, GerdLook up in the Integrated Authority File of the German National Library
Heerklotz, HeikoLook up in the Integrated Authority File of the German National Library
Issue Date: 2023
Type: Article
Language: English
Abstract: Lysolipids such as lauroyl, myristoyl, and palmitoyl lysophosphatidylcholine (LPC) insert into the outer leaflet of liposomes but do not flip to the inner leaflet over many hours. This way, they create asymmetry stress between the intrinsic areas of the two leaflets. We have studied how this stress is relaxed with particular emphasis on the budding and fission of small (diameter 20–30 nm) daughter vesicles (DVs). Asymmetric flow field-flow fractionation was utilized to quantify the extent of budding from large unilamellar vesicles after exposure to LPC. Budding starts at a low threshold of the order of 2 mol% LPC in the outer (and ≈0 mol% LPC in the inner) leaflet. We see reason to assume that the fractional fluorescence intensity from DVs is a good approximation for the fraction of membrane lipid, POPC, transferred into DVs. Accordingly, budding starts with a “budding power” of ≈6 POPC molecules budding off per LPC added, corresponding to a more than 10-fold accumulation of LPC in the outer leaflet of DVs to ≈24 mol%. As long as budding is possible, little strain is built up in the membranes, a claim supported by the lack of changes in limiting fluorescence anisotropy, rotational correlation time, and fluorescence lifetime of symmetrically and asymmetrically inserted TMA-DPH. At physiological osmolarity, budding is typically limited to 20–30% of budded fraction with some batch-to-batch variation, but independent of the LPC species. We hypothesize that the budding limit is determined by the excess area of the liposomes upon preparation, which is then used up upon budding given the larger area-to-volume ratio of smaller liposomes. As the mother vesicles approach ideal spheres, budding must stop. This is qualitatively supported by increased and decreased budding limits of osmotically predeflated and preinflated vesicles, respectively.
URI: https://opendata.uni-halle.de//handle/1981185920/113005
http://dx.doi.org/10.25673/111051
Open Access: Open access publication
License: (CC BY 4.0) Creative Commons Attribution 4.0(CC BY 4.0) Creative Commons Attribution 4.0
Journal Title: Biophysical journal
Publisher: Cell Press
Publisher Place: Cambridge, Mass.
Volume: 122
Issue: 20
Original Publication: 10.1016/j.bpj.2023.08.023
Page Start: 4011
Page End: 4022
Appears in Collections:Open Access Publikationen der MLU

Files in This Item:
File Description SizeFormat 
1-s2.0-S0006349523005544-main.pdf3.11 MBAdobe PDFThumbnail
View/Open