Laboratory of General Physiology, Harvard University, Cambridge.
J Gen Physiol. 1930 Nov 20;14(2):163-77. doi: 10.1085/jgp.14.2.163.
A survey of the published electrophoretic mobilities of certain mammalian red cells reveals that the isoelectric points accorded to these cells are the result of equilibria incidental to red cell destruction. The electrophoretic mobilities of normal washed sheep and human cells have now been studied in 0.85 per cent NaCl solutions from about pH 3.6 to 7.4. All measurements were made within 2 minutes of the preparation of the suspension of red cells. In no case was reversal of sign of charge observed under these conditions. Reversal of sign of charge occurred only after sufficient time had elapsed to permit sufficient adsorption of the products of red cell destruction. There is little change in mobility as the pH of the medium is decreased. Reversal of sign of charge does occur in the presence of normal and immune (anti-sheep) rabbit sera. The isoelectric point determined under these conditions does not appear to be connected specifically with the immune body but is perhaps associated with phenomena incidental to red cell destruction and the presence of serum. The characteristic lowering of mobility by amboceptor occurs, however, from pH 4.0 to pH 7.4. The curves of mobility plotted against pH for normal and for immune sera support the viewpoint that the identity of the isoelectric points for normal and sensitized sheep cells is not primarily concerned with the immune reaction. It is most unlikely that an "albumin" or a "globulin" surface covers red cells with a complete protein film. Although serum protein reacts with red cells in acid solutions, this is not demonstrable for gelatin. The lowering of mobility usually ascribed to anti-sheep rabbit serum may also occur, but to a lesser degree, in normal rabbit serum. This diminution of mobility is not, in the first place, associated with sensitization to hemolysis induced by complement. This supports the view that only a very small part of the red cell surface need be changed in order to obtain complete hemolysis in the presence of complement.
对某些哺乳动物红细胞发表的电泳迁移率的调查表明，这些细胞的等电点是红细胞破坏时偶然达到的平衡结果。现在已经在 0.85%氯化钠溶液中研究了正常洗涤的绵羊和人红细胞的电泳迁移率，pH 值约为 3.6 至 7.4。所有测量都是在红细胞悬浮液制备后 2 分钟内进行的。在这些条件下，没有观察到电荷符号的反转。只有在足够的时间过去，允许红细胞破坏产物充分吸附后，才会发生电荷符号的反转。随着介质 pH 值的降低，迁移率变化不大。在正常和免疫（抗绵羊）兔血清存在下，电荷符号确实会反转。在这些条件下确定的等电点似乎与免疫球蛋白体没有具体联系，而是可能与红细胞破坏和血清存在时的偶然现象有关。然而，在 pH 值为 4.0 到 pH 值为 7.4 时，会发生补体的特征性迁移率降低。正常和免疫血清的迁移率与 pH 值的关系曲线支持这样一种观点，即正常和致敏绵羊细胞的等电点的同一性与免疫反应没有直接关系。极不可能有一层完整的蛋白质膜覆盖红细胞的“白蛋白”或“球蛋白”表面。尽管血清蛋白在酸性溶液中与红细胞反应，但在明胶中则不能证明这一点。通常归因于抗绵羊兔血清的迁移率降低也可能发生，但程度较小，在正常兔血清中也是如此。这种迁移率的降低首先与补体引起的溶血的致敏无关。这支持这样一种观点，即只有一小部分红细胞表面需要改变，才能在补体存在的情况下获得完全溶血。
