TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Mladenov, Nikola
A1  - Petrova, Svetla
A1  - Mladenova, Kirilka
A1  - Bozhinova, Desislava
A1  - Moskova-Doumanova, Veselina
A1  - Topouzova-Hristova, Tanya
A1  - Videv, Pavel
A1  - Veleva, Ralitsa
A1  - Kostadinova, Aneliya
A1  - Staneva, Galya
A1  - Andreeva, Tonya
A1  - Doumanov, Jordan
T1  - Miscibility of hBest1 and sphingomyelin in surface films – a prerequisite for interaction with membrane domains
JF  - Colloids and surfaces : an international journal devoted to fundamental and applied research on colloid and interfacial phenomena in relation to systems of biological origin. B, Biointerfaces
N2  - Human bestrophin-1 (hBest1) is a transmembrane Ca2+- dependent anion channel, associated with the transport of Cl−, HCO3- ions, γ-aminobutiric acid (GABA), glutamate (Glu), and regulation of retinal homeostasis. Its mutant forms cause retinal degenerative diseases, defined as Bestrophinopathies. Using both physicochemical - surface pressure/mean molecular area (π/A) isotherms, hysteresis, compressibility moduli of hBest1/sphingomyelin (SM) monolayers, Brewster angle microscopy (BAM) studies, and biological approaches - detergent membrane fractionation, Laurdan (6-dodecanoyl-N,N-dimethyl-2-naphthylamine) and immunofluorescence staining of stably transfected MDCK-hBest1 and MDCK II cells, we report:

1) Ca2+, Glu and GABA interact with binary hBest1/SM monolayers at 35 °C, resulting in changes in hBest1 surface conformation, structure, self-organization and surface dynamics. The process of mixing in hBest1/SM monolayers is spontaneous and the effect of protein on binary films was defined as “fluidizing”, hindering the phase-transition of monolayer from liquid-expanded to intermediate (LE-M) state;

2) in stably transfected MDCK-hBest1 cells, bestrophin-1 was distributed between detergent resistant (DRM) and detergent-soluble membranes (DSM) - up to 30 % and 70 %, respectively; in alive cells, hBest1 was visualized in both liquid-ordered (Lo) and liquid-disordered (Ld) fractions, quantifying protein association up to 35 % and 65 % with Lo and Ld. Our results indicate that the spontaneous miscibility of hBest1 and SM is a prerequisite to diverse protein interactions with membrane domains, different structural conformations and biological functions.
KW  - hBest1
KW  - sphingomyelin
KW  - surface films
KW  - lipid rafts
KW  - laurdan
KW  - MDCK II cells
Y1  - 2020
SN  - 0927-7765
SS  - 0927-7765
U6  - https://doi.org/10.1016/j.colsurfb.2020.110893
DO  - https://doi.org/10.1016/j.colsurfb.2020.110893
VL  - 189
SP  - 1
EP  - 9
S1  - 9
PB  - Elsevier
CY  - Amsterdam
ER  -