| Author/Editor | Žuvić-Butorac, Marta; Batista, Urška; Schara, Milan | |
| Title | EPR spectra of cell membranes: a comparative study of erythrocytes and fibroblasts | |
| Type | članek | |
| Source | Period Biol | |
| Vol. and No. | Letnik 103, št. 3 | |
| Publication year | 2001 | |
| Volume | str. 235-40 | |
| Language | eng | |
| Abstract | Background and purpose: The purpose of the work was to give a description of erythrocyte and fibroblast membrane hpid phase in terms of molecular ordering and mobility, using the method of numerical analysis of electron paramagnetic resonance, EPR, spectra. Material and methods: Bovine erythrocytes, isolated from fresh blood, and two types of cell cultured fibroblasts- baby hamster kidney (BHK), and hamster lung (V 79)- cultured fibroblasts were labeled with lipophilic nitroxide spin probe, methyl ester of 5-doxyl palmitate (MeFASL(10,3)). The analysis of the measured EPR spectra was performed using line shape simulation with the calculated spectra with different mobility restrictions in lipid bilayer structures. The cell membrane lipid phase characteristics were determined in terms of two domain classes, described by different molecular ordering, dynamics, as well asrelative domain population. The experimental conditions like temperature, buffer pH, calcium concentration, and osmolarity were varied in order to detect the possible adjustment of membrane organization. Results: The plasma membrane of fibroblasts showed a higher overall fluidity than the erythrocyte membrane. The difference was indicated by a lower ordering and motional restrictions in the lipid phase, as well as by lower participation of the ordered domain class. With increased temperature, a typical decrease in ordering, as well as the decreased participation for the ordered phase, were observed in both types of cells. The imposed variations of pH, calcium concentration, and osmolality promoted different perturbations of the investigated cell membrane characteristics, though the most pronounced was the effect on the population of lateral domains. (Abstract truncated at 2000 characters). | |
| Descriptors | ERYTHROCYTES FIBROBLASTS CELL MEMBRANE PERMEABILITY ELECTRON SPIN RESONANCE SPECTROSCOPY SPIN LABELS TEMPERATURE HYDROGEN-ION CONCENTRATION CALCIUM |