Motais R, Baroin A, Baldy S
J Membr Biol. 1981;62(3):195-206. doi: 10.1007/BF01998165.
A 15% of band 3 protein, the assumed chloride channel, is associated with spectrin, the major peripheral protein of a lattice located at the red cell membrane-cytosol interface, the present study was undertaken to evaluate whether a rearrangement of the lattice modifies the functional property of band 3 protein. Such a rearrangement was modulated by depletion of cell ATP and/or by accumulation of Ca2+ ions within the cell. ATP depletion induces an inhibition of the electroneutral one-for-one chloride exchanges. Neither the modification of red cell morphology due to ATP depletion (discocyte-echinocyte transformation) nor a direct effect of the decrease in internal ATP level can account for this inhibition. On the other hand, it seems reasonable to consider that inhibition is related to the changes in membrane protein organization (formation of heteropolymers) induced by the decrease in ATP level. But it does not appear that the degree of inhibition is modified when this altered assembly of membrane protein is stabilized by disulfide linkages. Accumulation of Ca2+ ions in the cell at a relatively low concentration (10 micro M range) inhibits chloride exchange without apparent modification of the assembly of membrane proteins. This effect of calcium on chloride exchanges is speculatively denoted as a "direct" effect of calcium. Calcium loading of fresh red cells at higher concentrations (500 to 1000 micro M) obtained by use of the ionophore A23187 induces a very strong inhibition of chloride exchanges. In this case, inhibition can be reasonably accounted for by two simultaneous effects of calcium: a "direct" effect which explains half of the inhibition and an "indirect effect due to the formation of membrane protein complexes stabilized by covalent crosslinkages (activation by Ca2+ ions of a transglutaminase). It is interesting to note that intracellular calcium, whatever the level, inhibits electroneutral exchanges of chloride but increases net chloride movements.
15%的带3蛋白（假定的氯离子通道）与血影蛋白相关，血影蛋白是位于红细胞膜 - 胞质溶胶界面的晶格的主要外周蛋白。本研究旨在评估晶格的重排是否会改变带3蛋白的功能特性。这种重排通过细胞ATP的消耗和/或细胞内Ca2 +离子的积累来调节。ATP消耗会抑制电中性的一对一氯离子交换。由于ATP消耗导致的红细胞形态改变（盘状细胞 - 棘状细胞转变）以及内部ATP水平降低的直接影响都不能解释这种抑制作用。另一方面，认为这种抑制与ATP水平降低引起的膜蛋白组织变化（异聚物形成）有关似乎是合理的。但是，当通过二硫键稳定这种改变的膜蛋白组装时，抑制程度似乎并未改变。细胞内相对低浓度（10微摩尔范围）的Ca2 +离子积累会抑制氯离子交换，而膜蛋白组装没有明显改变。钙对氯离子交换的这种作用被推测为钙的“直接”作用。通过使用离子载体A23187使新鲜红细胞在较高浓度（500至1000微摩尔）下加载钙会导致氯离子交换受到非常强烈的抑制。在这种情况下，抑制作用可以合理地由钙的两种同时作用来解释：一种“直接”作用解释了一半的抑制作用，另一种“间接作用”是由于通过共价交联稳定的膜蛋白复合物的形成（Ca2 +离子激活转谷氨酰胺酶）。有趣的是，无论细胞内钙水平如何，它都会抑制氯离子的电中性交换，但会增加净氯离子移动。
