The pore forming capacity of Sticholysin I in dipalmitoyl phosphatidyl vesicles is tuned by osmotic stress
Date
2017
Type:
Artículo
item.page.extent
7
item.page.accessRights
item.contributor.advisor
ORCID:
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
item.page.isbn
item.page.issn
item.page.issne
item.page.doiurl
item.page.other
item.page.references
Abstract
The osmotic condition modulates the properties of liposomes, particularly those related to their
stability and response to external agents such as membrane-active proteins or peptides. In a
previous work, we have demonstrated that an osmotic shock can increase, per se, water
influx/efflux and the exit of the fluorophore calcein entrapped in the aqueous pool of
dipalmitoylphosphatidylcholine (DPPC) and DPPC:sphingomyelin (SM) large unilamellar vesicles
(LUVs), suggesting a loss of integrity of the liposome bilayer. In the present work, we have extended
our study in order to assess how an osmotic imbalance prior to or synchronous with the addition of
a recombinant variant of the pore-forming toxin sticholysin I (rSt I) modifies its pore forming capacity
in DPPC and DPPC:SM (1:1) LUVs. Our results conclusively show the capacity of hypotonic gradients
to improve the pore forming capacity of rSt I molecules, even in pure DPPC liposomes, rendering
pore-formation less dependent on the presence of sphyngomyelin. In fact, non-active toxins in DPPC
liposomes become active by a hypotonic imbalance in a similar way to those containing SM as a
second component.
Description
item.page.coverage.spatial
item.page.sponsorship
Citation
Ahumada M, Calderon C, Lissi E, Alvarez C, Lanio ME, Pazos F. The pore forming capacity of Sticholysin I in dipalmitoyl phosphatidyl vesicles is tuned by osmotic stress. Chem Phys Lipids. 2017 Mar;203:87-93. doi: 10.1016/j.chemphyslip.2016.12.005.
Keywords
Sticholysins, Osmotic shock, Liposomes, Permeability