© 2005 The Japanese Biochemical Society
Regular Paper |
High-Pressure–Induced Hemolysis in Papain-Digested Human Erythrocytes Is Suppressed by Cross-Linking of Band 3 via Anti–Band 3 Antibodies
Department of Chemistry, Faculty of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180
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Upon exposure of human erythrocytes to a high pressure of 200 mPa, both hemolysis and vesiculation occur. The hemolysis of erythrocytes at 200 mPa was enhanced by removal of sialic acids from the membrane surface with papain. However, such enhancement was suppressed by cross-linking of band 3 via an anti–band 3 antibody (AB3A), which recognizes the exofacial domain of band 3, or by clustering of band 3 via Zn2+. On the other hand, the size of high-pressure–induced vesicles increased from 423 to 525 nm in diameter upon exposure to papain of erythrocytes, but decreased to 444 nm with following treatment with AB3A. In these vesicles, the content of spectrin relative to band 3 was almost the same. Furthermore, the band 3–cytoskeleton interactions in erythrocyte membranes remained unaltered upon treatment with papain and AB3A. Flow cytometric analysis demonstrated that papain-pretreated erythrocytes mainly produce open ghosts at 200 mPa and that the production of such open ghosts is suppressed by AB3A. Thus, upon removal of negative charges from the membrane surface, open ghosts are readily produced due to the release of larger vesicles under pressure. Upon cross-linking of band 3 via AB3A, however, the release of smaller vesicles at 200 mPa is facilitated so that high-pressure–induced hemolysis is suppressed.