Yamaguchi Takeo, Satoh Ituki, Ariyoshi Naoko, Terada Shigeyuki
Department of Chemistry, Faculty of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180.
J Biochem. 2005 Apr;137(4):535-41. doi: 10.1093/jb/mvi060.
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.
当人类红细胞暴露于200兆帕的高压下时，溶血和囊泡化都会发生。用木瓜蛋白酶去除膜表面的唾液酸可增强红细胞在200兆帕时的溶血作用。然而，通过抗带3抗体（AB3A）使带3交联（AB3A识别带3的细胞外结构域）或通过Zn2+使带3聚集，可抑制这种增强作用。另一方面，红细胞暴露于木瓜蛋白酶后，高压诱导的囊泡直径从423纳米增加到525纳米，但在用AB3A处理后又减小到444纳米。在这些囊泡中，血影蛋白相对于带3的含量几乎相同。此外，用木瓜蛋白酶和AB3A处理后，红细胞膜中带3与细胞骨架的相互作用保持不变。流式细胞术分析表明，经木瓜蛋白酶预处理的红细胞在200兆帕时主要产生开放型血影，而AB3A可抑制这种开放型血影的产生。因此，当从膜表面去除负电荷时，由于在压力下释放出较大的囊泡，容易产生开放型血影。然而，通过AB3A使带3交联时，在200兆帕时促进了较小囊泡的释放，从而抑制了高压诱导的溶血。
