Abstract
The packing of lipids comprising a cell membrane, known as lipid order, has been under increasing scrutiny due to continuous findings of its biological significance. There is extensive literature detailing the changes in lipid order, and multiple temperature-induced phase transitions have been clarified. However, these experiments have not considered common external factors, such as hypo-osmotic stress and protein insertion. To fill these gaps in our knowledge, Red Blood Cell (RBC) membranes stained with membrane probes were investigated by general polarization (GP) and anisotropy (p). We evaluated RBC membranes under hypo-osmotic shock, and membranes with pore-forming toxins. Significant changes in lipid order were observed after exposure to hypo-osmotic stress or insertion of pore-forming toxins, echoing temperature-induced phase transitions of lipids in membranes. We hypothesized a short-range interaction model to explain the significant changes in lipid order under hypo-osmotic shock, together with a hydrophobic mismatch to explain the changes observed upon protein insertion. Our findings may provide a better understanding of the modulation of physiological functionals, such as transport and signaling, by physical cues and interactions with drugs or other bioactive molecules.
Original language | American English |
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State | Published - 12 Jul 2023 |