Structural and functional relationship of red blood cell protein 4.1 to synapsin I.
Structural and functional relationship of red blood cell protein 4.1 to synapsin I.
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红细胞蛋白 4.1 与突触蛋白 I 的结构和功能关系。
DOI：
10.1152/ajpcell.1987.253.4.c500
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Goodman,SR
中科院分区：
文献类型：
--
作者：
Krebs,KE;Prouty,SM;Zagon,IS;Goodman,SR
神经元特异性蛋白突触蛋白I与红细胞蛋白4.1密切相关。系统比较了红细胞蛋白4.1和突触蛋白I的结构和功能特性。通过竞争性定量斑点试验测定，突触蛋白I与rbc 4.1抗血清和突触蛋白I抗血清的交叉反应性大约有三个数量级的差异。二维胰凝乳蛋白酶碘肽图谱分析表明，rbc 4.1和突触蛋白I之间的肽同源性有限（约34%斑点重叠）。去磷酸化的突触蛋白I与脑血影蛋白（240/235）饱和结合，估计解离常数（Kd）为700 nM，最大结合能力为4 mol突触蛋白I/mol血影蛋白四聚体，与4.1与rbc血影蛋白结合的亲和力和化学计量相似。突触蛋白I被发现通过低角度旋转阴影结合到脑血影蛋白四聚体的末端，类似于4.1结合到红细胞血影蛋白。总之，突触蛋白I在结构上和免疫学上与rbc 4.1不同，但在血影蛋白结合特征方面与rbc 4.1具有功能相似性。
It has been suggested that the neuron specific protein synapsin I is closely related to red blood cell (rbc) protein 4.1. A systematic comparison of the structural and functional properties of rbc protein 4.1 and synapsin I has been carried out. There is approximately a three order of magnitude difference in cross reactivity of synapsin I with rbc 4.1 antiserum vs. synapsin I antiserum, as determined by a competitive quantitative dot assay. Two-dimensional chymotryptic iodopeptide mapping analysis demonstrated limited peptide homology (approximately 34% spot overlap) between rbc 4.1 and synapsin I. Dephosphorylated synapsin I binds saturably to brain spectrin (240/235) with an estimated dissociation constant (Kd) of 700 nM and a maximal binding capacity of 4 mol synapsin I/mol spectrin tetramer, similar to the affinity and stoichiometry of 4.1 binding to rbc spectrin. Synapsin I was found to bind to the terminal ends of the brain spectrin tetramer by low-angle rotary shadowing, analogous to 4.1 binding to rbc spectrin. In summary, synapsin I is structurally and immunologically distinct from rbc 4.1, yet shares functional similarities with rbc 4.1 with respect to its spectrin binding characteristics.