Abstract Title
Lipid Order in Red Blood Cell Membranes Exposed to Hypo-Osmotic Stress and Self-Inserting Pore-Forming Proteins
Additional Funding Sources
Research presented in this poster is supported by the National Institutes of Health IDeA INBRE and COBRE Programs, NIH Grants No. P20GM103408, P20GM109095, and P20GM148321 (National Institute of General Medical Sciences). Additional funding was provided by the National Science Foundation (grant number 1554166) and the Idaho State Board of Education.
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.
Lipid Order in Red Blood Cell Membranes Exposed to Hypo-Osmotic Stress and Self-Inserting Pore-Forming Proteins
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.