Release of spectrin-containing vesicles from human erythrocyte ghosts by dimyristoylphosphatidylcholine.
Membrane vesicles, which were released from human erythrocyte ghosts by dimyristoylphosphatidylcholine (DMPC), showed a protein composition similar to that of the erythrocyte membrane, despite a reduction of in spectrin content. The spectrin content of vesicles decreased with increasing hemoglobin concentration within ghost membranes, but increased upon exposure of hemoglobin-free ghosts to a pressure of 100 MPa. The ESR spectra of spin-labeled membrane proteins showed that membrane proteins in ghosts became unfolded at high pressure. Furthermore, spectrin-poor and protein 4.1-rich vesicles were released by DMPC from diamide-treated ghosts in which spectrin was cross-linked and stabilized. Taking into account that the spectrin tetramer is stabilized by hemoglobin [Liu and Palek (1984) J. Biol. Chem. 259, 11556-11562], these results suggest that the spectrin content of DMPC-induced vesicles from erythrocyte ghosts increases with increasing instability of the cytoskeletal network in parent cells.
Department of Chemistry, Faculty of Science, Fukuoka University, Jonan-ku.
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Yamaguchi
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Yamamoto
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Kimoto
D000199:Actins / Q000737:chemistry; D003598:Cytoskeletal Proteins / Q000737:chemistry; D003958:Diamide / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D004910:Erythrocyte Membrane / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D007477:Ions; D008081:Liposomes / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry; D011312:Pressure; D017510:Protein Folding; D013049:Spectrin / Q000737:chemistry*
D000199:Actins; D003598:Cytoskeletal Proteins; D006454:Hemoglobins; D007202:Indicators and Reagents; D007477:Ions; D008081:Liposomes; D008565:Membrane Proteins; D003958:Diamide; D013049:Spectrin; D004134:Dimyristoylphosphatidylcholine