TY  - JOUR
AU  - de Santis, Augusta
AU  - Vitiello, Giuseppe
AU  - Appavou, Marie-Sousai
AU  - Scoppola, Ernesto
AU  - Fragneto, Giovanna
AU  - Barnsley, Lester C.
AU  - Clifton, Luke A.
AU  - Ottaviani, Maria Francesca
AU  - Paduano, Luigi
AU  - Russo Krauss, Irene
AU  - D’Errico, Gerardino
TI  - Not just a fluidifying effect: omega-3 phospholipids induce formation of non-lamellar structures in biomembranes
JO  - Soft matter
VL  - 16
IS  - 46
SN  - 1744-6848
CY  - London
PB  - Royal Soc. of Chemistry
M1  - FZJ-2020-04861
SP  - 10425-10438
PY  - 2020
AB  - Polyunsaturated omega-3 fatty acid docosahexaenoic acid (DHA) is found in very high concentrations in a few peculiar tissues, suggesting that it must have a specialized role. DHA was proposed to affect the function of the cell membrane and related proteins through an indirect mechanism of action, based on the DHA-phospholipid effects on the lipid bilayer structure. In this respect, most studies have focused on its influence on lipid-rafts, somehow neglecting the analysis of effects on liquid disordered phases that constitute most of the cell membranes, by reporting in these cases only a general fluidifying effect. In this study, by combining neutron reflectivity, cryo-transmission electron microscopy, small angle neutron scattering, dynamic light scattering and electron paramagnetic resonance spectroscopy, we characterize liquid disordered bilayers formed by the naturally abundant 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and different contents of a di-DHA glycero-phosphocholine, 22:6-22:6PC, from both a molecular/microscopic and supramolecular/mesoscopic viewpoint. We show that, below a threshold concentration of about 40% molar percent, incorporation of 22:6-22:6PC in the membrane increases the lipid dynamics slightly but sufficiently to promote the membrane deformation and increase of multilamellarity. Notably, beyond this threshold, 22:6-22:6PC disfavours the formation of lamellar phases, leading to a phase separation consisting mostly of small spherical particles that coexist with a minority portion of a lipid blob with water-filled cavities. Concurrently, from a molecular viewpoint, the polyunsaturated acyl chains tend to fold and expose the termini to the aqueous medium. We propose that this peculiar tendency is a key feature of the DHA-phospholipids making them able to modulate the local morphology of biomembranes.
LB  - PUB:(DE-HGF)16
C6  - 33165495
UR  - <Go to ISI:>//WOS:000596710100004
DO  - DOI:10.1039/D0SM01549K
UR  - https://juser.fz-juelich.de/record/888343
ER  -