Structure and thermotropic phase behaviour of detergent-resistant membrane raft fractions isolated from human and ruminant erythrocytes

摘要: Abstract Detergent-resistant membrane raft fractions have been prepared from human, goat, and sheep erythrocyte ghosts using Triton X-100. The structure thermotropic phase behaviour of the examined by freeze-fracture electron microscopy synchrotron X-ray diffraction methods. are found to consist vesicles multilamellar structures indicating considerable rearrangement original ghost membrane. Few membrane-associated particles typical replicas intact membranes observed in fracture planes. Synchrotron studies during heating cooling scans showed that formed stacks all three species d-spacings about 6.5 nm. These can be distinguished peaks corresponding 5.5 nm, which were assigned scattering single bilayer on basis temperature dependence their compared with arrangements. spacings obtained vesicular suspensions were, average, more than 0.5 nm greater arrangements they derived. trypsinization human results a small decrease lamellar d-spacing, but rafts trypsinized exhibit an additional repeat 0.4 less coinciding untreated ghosts. separation two (d = 6.00; 5.77 nm), produce band almost identical An examination dispersions total polar lipid extracts detergent-resistant preparations reversible inverted hexagonal coexisting takes place upon above 30 °C. Non-lamellar phases not erythrocytes or heated up 55 °C, suggesting arrangement is imposed these lipids interaction non-lipid components and/or topology survives detergent treatment.