Studies of factors regulating the ageing of human erythrocytes--V. The role of vesiculation in the loss of membrane-bound sialic acid.
1. Erythrocytes aged in vitro in protein-free media with and without leukocytes, release glycopeptides and vesicles. 2. Addition of soybean trypsin inhibitor (SbTI) blocks almost completely the release of glycopeptides but not the vesiculation. 3. Vesicles appear as a heterogeneous population with a diameter of 125 +/- 20 nm and with a lower content of N-acetylneuraminic acid (NAN) than ghosts of the original erythrocytes. 4. The NAN:phosphorus and NAN:cholesterol ratios in the vesicles are lower than in intact membranes. 5. The results indicate a redistribution of membrane components during in vitro erythrocyte incubation and the major importance of sialopeptides release in comparison with vesiculation.
D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism*; D004905:Erythrocyte Aging; D006020:Glycopeptides / Q000378:metabolism*; D006801:Humans; D012794:Sialic Acids / Q000378:metabolism*
D006020:Glycopeptides; D012794:Sialic Acids