Nanri H, Hamasaki N, Minakami S
J Biol Chem. 1983 May 10;258(9):5985-9.
Transport of pyridoxal 5-phosphate (PLP) into erythrocytes was inhibited by inhibitors of anion transport including stilbene disulfonate compounds, indicating that it is mediated by Band 3 protein. When erythrocytes were treated with PLP and large amounts of free lysine and NaBH4, two membrane-spanning fragments of Band 3 (Mr = 17,000 and 35,000) were specifically labeled. When the cells were pretreated with 4,4'-dinitrostilbene 2,2'-disulfonate, the labeling in the 35,000-dalton fragment was inhibited. Erythrocytes labeled by PLP in both the 17,000- and 35,000-dalton fragments transported PLP at a decreased rate, whereas the cells labeled in only the 17,000-dalton fragment had essentially the same transport activity as the control when 4,4'-dinitrostilbene 2,2'-disulfonate was removed. The extent of inhibition of transport of inorganic phosphate in the labeled cells was similar to that of PLP. The results indicate that the 35,000-dalton fragment participates in the anion transport of the cell membrane.
包括二苯乙烯二磺酸盐化合物在内的阴离子转运抑制剂可抑制磷酸吡哆醛（PLP）进入红细胞，这表明其转运由带3蛋白介导。当用PLP、大量游离赖氨酸和硼氢化钠处理红细胞时，带3的两个跨膜片段（Mr = 17,000和35,000）被特异性标记。当细胞用4,4'-二硝基二苯乙烯2,2'-二磺酸盐预处理时，35,000道尔顿片段中的标记被抑制。在17,000道尔顿和35,000道尔顿片段中均被PLP标记的红细胞转运PLP的速率降低，而仅在17,000道尔顿片段中被标记的细胞在去除4,4'-二硝基二苯乙烯2,2'-二磺酸盐后其转运活性与对照基本相同。标记细胞中无机磷酸转运的抑制程度与PLP相似。结果表明，35,000道尔顿片段参与细胞膜的阴离子转运。
