Erythrocyte bisulfite transport.
Erythrocyte bisulfite transport.
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红细胞亚硫酸氢盐转运。
DOI：
10.1016/0005-2736(89)90048-5
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Misiewicz,VM
中科院分区：
文献类型：
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作者：
Labotka,RJ;Galanter,W;Misiewicz,VM
人红细胞阴离子转运蛋白（带3蛋白）对不同化学结构的阴离子的转运率范围很广，表明该蛋白对化学上类似于其天然底物碳酸氢盐的阴离子具有高度选择性。为了验证这一假设，将亚硫酸氢盐（HSO 3 −1）（一种碳酸氢盐类似物）的流入量与氯化物、硫酸盐和碳酸氢盐的流入量进行了比较，这是通过等渗铵盐溶液中的胶体渗透溶解技术测量的。在氯化物溶液中诱导的裂解时间（约10分钟）显着加速到0.6分钟，通过添加少量（5 mM）的碳酸氢盐，由阴离子转运途径诱导的胶体渗透裂解的效果特征。在碳酸氢盐溶液中的溶解非常迅速（0.09分钟），并被乙酰唑胺（2.9分钟）明显抑制。在亚硫酸氢盐溶液中的裂解自发发生（2.2分钟），但通过加入5 mM碳酸氢盐显著加速至与氯化物（0.56分钟）相似的时间。相比之下，硫酸盐诱导的裂解极其缓慢（在碳酸氢盐存在下，在40分钟时< 10%裂解）。预孵育的红细胞与SITS，阴离子交换抑制剂，防止溶解氯化物，但没有影响溶解碳酸氢盐，表明溶解碳酸氢盐主要是通过扩散，而不是阴离子转运。SITS处理的红细胞消除了碳酸氢盐的催化作用，在溶解过程中的亚硫酸氢盐，表明阴离子转运的亚硫酸氢盐和扩散的共轭酸的形式SO2都有助于总膜通量。当考虑到扩散的贡献时，亚硫酸氢盐通过阴离子交换途径流入的速率比硫酸盐快至少100倍。
The wide range of transport rates for anions of differing chemical structure by the human erythrocyte anion transport protein (Band 3 protein) suggests that this protein is highly selective for anions that chemically resemble its natural substrate bicarbonate. To test this hypothesis, the influx of bisulfite (HSO3−1), a bicarbonate analog, was compared to influxes of chloride, sulfate, and bicarbonate, as measured by the technique of colloid osmotic lysis in isotonic ammonium salt solution. The lysis time induced in chloride solution (⪢ 10 min) was markedly accelerated to 0.6 min by the addition of small amounts (5 mM) of bicarbonate, an effect characteristic of colloid osmotic lysis induced by the anion transport pathway. Lysis in bicarbonate solution was extremely rapid (0.09 min), and was markedly inhibited by acetazolamide (2.9 min). Lysis in bisulfite solution occurred spontaneously (2.2 min) but was markedly accelerated to a time similar to that of chloride (0.56 min) by addition of 5 mM bicarbonate. In contrast, sulfate induced lysis was extremely slow (< 10% lysis at 40 min in the presence of bicarbonate). Preincubation of erythrocytes with SITS, an inhibitor of anion exchange, prevented lysis by chloride, but had no effect on lysis by bicarbonate, indicating that lysis by bicarbonate was predominantly through diffusion and not anion transport. SITS treatment of erythrocytes eliminated the catalytic effect of bicarbonate during lysis by bisulfite, indicating that anion transport of bisulfite and diffusion of the conjugate acid in the form of SO2both contribute to the total membrane flux. When the contribution of diffusion is taken into account, the rate of bisulfite influx through the anion exchange pathway is at least 100-fold faster than that for sulfate.