Heterogeneity in the fluidity of intact erythrocyte membrane and its homogenization upon hemolysis.

摘要: Abstract Intact erythrocytes were spin-labeled with various classes of phospholipid label. The ESR spectrum for phosphatidylcholine spin label was distinctly different from those phosphatidylserine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidic acid labels. overall splitting the former (52.5 G) markedly larger than others (approx. 47 G), suggesting a more rigid bilayer phase fluid phosphatidylethanolamine phosphatidylserine phases in erythrocyte membrane. Evidence asymmetric distribution phospholipids membrane obtained. Spin-labeled incorporated into reduced immediately by cystein Fe3+, while reduction very slow. present results therefore suggest fluidity membrane; outer layer inner layer. heterogeneity lipid structure also manifested temperature dependence fluidity. showed two inflection points at 18 33 °C, that had only one transition 30 °C. When hemolyzed, marked difference spectra disappeared, indicating homogenization heterogeneous Mg2+ or Mg 2+ + ATP prevented hemolysis-induced spectral changes. Ca2+ did not prevent acted antagonistically to Mg2+. preservation nullified trypsin, pronase N- ethylmaleimide added inside cell. Some proteins may be involved maintaining structure. protecting action dependent on hemolysis temperature, starting decrease °C vanishing 40 study suggests intact membranes arises interactions between lipids constituents proteins. Concentration cholesterol partly contribute heterogeneity.