Red blood cell band 3. Lysine 539 and lysine 851 react with the same H2DIDS (4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonic acid) molecule.
Red blood cell band 3. Lysine 539 and lysine 851 react with the same H2DIDS (4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonic acid) molecule.
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DOI：
10.1016/s0021-9258(17)42114-4
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发表时间：
1994-01
期刊：
影响因子：
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通讯作者：
K. Okubo;D. Kang;N. Hamasaki;M. Jennings
中科院分区：
文献类型：
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作者：
K. Okubo;D. Kang;N. Hamasaki;M. Jennings
红细胞膜上的带3蛋白催化被二苯乙烯二磺酸衍生物H2DIDS（4,4 ' -二异硫氰酸二氢二苯乙烯-2,2 ' -二磺酸）抑制的阴离子交换。每个95000 - da波段3多肽有一个H2DIDS结合位点。单键H2DIDS分子可以与2种不同的赖氨酸残基共价反应。与H2DIDS共价反应的2种赖氨酸已通过测序[3H]H2DIDS标记的细胞的人类带3片段直接定位。与定点诱变研究一致，与Lys-539发生的共价反应最快。反应较慢的是Lys-851，已知它是另一种阴离子运输抑制剂磷酸吡哆醛的主要结合位点（Kawano et al., 1988）。这些结果表明，蛋白质折叠使这两个残基足够接近，从而与相同的H2DIDS分子发生共价反应。除了确定与H2DIDS反应的残基外，这些研究还确定了条带3中新的原位蛋白水解裂解位点。
The band 3 protein of the red blood cell membrane catalyzes anion exchange that is inhibited by the stilbenedisulfonate derivative H2DIDS (4,4‘-diisothiocyanodihydrostilbene-2,2‘-disulfonic acid). There is one H2DIDS binding site per 95,000-Da band 3 polypeptide. The single bound H2DIDS molecule can react covalently with 2 different lysine residues. The 2 lysines that react covalently with H2DIDS have been localized directly by sequencing fragments of human band 3 from cells labeled with [3H]H2DIDS. The most rapid covalent reaction is with Lys-539, in agreement with site-directed mutagenesis studies. The slower reaction is with Lys-851, which is known to be the primary site of binding of another anion transport inhibitor, pyridoxal phosphate (Kawano et al., 1988). These results indicate that the protein is folded to bring these 2 residues into close enough proximity to react covalently with the same H2DIDS molecule. In addition to defining the residues that react with H2DIDS, these studies have also defined new in situ proteolytic cleavage sites in band 3.