| Full text | |
| Author(s): |
Donato, Maressa
[1, 2]
;
Soto, Carmen
[3]
;
Lanio, Maria Eliana
[3]
;
Itri, Rosangela
[1]
;
Alvarez, Carlos
[3]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Inst Fis, Sao Paulo, SP - Brazil
[2] Ctr Laser & Applicat, Nucl & Energy Res Inst, Sao Paulo - Brazil
[3] Univ La Habana, Fac Biol, Ctr Estudio Proteinas, Havana 10400 - Cuba
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Toxicon; v. 204, p. 44-55, DEC 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
Sticholysin I (StI) is a pore-forming toxin (PFT) belonging to the actinoporin protein family characterized by high permeabilizing activity in membranes. StI readily associates with sphingomyelin (SM)-containing membranes originating pores that can lead to cell death. Binding and pore-formation are critically dependent on the physicochemical properties of membrane. 1-palmitoyl-2-oleoylphosphatidylcholine hydroperoxide (POPC-OOH) is an oxidized phospholipid (OxPL) containing an -OOH moiety in the unsaturated hydrocarbon chain which orientates towards the bilayer interface. This orientation causes an increase in the lipid molecular area, lateral expansion and decrease in bilayer thickness, elastic and bending modulus, as well as modification of lipid packing. Taking advantage of membrane structural changes promoted by POPC-OOH, we investigated its influence on the permeabilizing ability of StI. Here we report the action of StI on Giant Unilamellar Vesicles (GUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and SM containing increasing amount of POPC-OOH to assess vesicle permeability changes when compared to OxPL-lacking membranes. Inclusion of POPC-OOH in membranes did not promote spontaneous vesicle leaking but resulted in increased membrane permeability due to StI action. StI activity did not modify the fluid-gel phase coexistence boundaries neither in POPC:SM or POPCOOH:SM membranes. However, the StI insertion mechanism in membrane seems to differ between POPC:SM and POPC-OOH:SM mixtures as suggested by changes in the time course of monolayer surface tension measurements, even though a preferable binding of the toxin to OxPL-containing systems could not be here demonstrated. In summary, modifications in the membrane imposed by lipid hydroperoxidation favor StI permeabilizing activity. (AU) | |
| FAPESP's process: | 17/08460-1 - Stability and modification of liposomal lipidic systems containing oxidized lipids upon binding and activity of the pore-forming protein sticholysin I |
| Grantee: | Rosangela Itri |
| Support Opportunities: | Research Grants - Visiting Researcher Grant - International |
| FAPESP's process: | 16/01379-1 - Sticholysins from the sea anemone Stichodactyla Helianthus: interaction with nucleic acids for biotechnology application |
| Grantee: | Rosangela Itri |
| Support Opportunities: | Research Grants - Visiting Researcher Grant - International |