The interaction of neurotoxin derivatives with either acetylcholine receptor or a monoclonal antibody. An electron-spin-resonance study.
The interaction of neurotoxin derivatives with either acetylcholine receptor or a monoclonal antibody. An electron-spin-resonance study.
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神经毒素衍生物与乙酰胆碱受体或单克隆抗体的相互作用。
DOI：
10.1111/j.1432-1033.1984.tb08063.x
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
A. Ménez
中科院分区：
文献类型：
--
作者：
A. Rousselet;G. Faure;J. Boulain;A. Ménez
制备了五种在单个氨基上自旋标记的黑颈眼镜蛇毒素α衍生物。毒素衍生物通过离子交换和高压液相色谱法纯化至均一。修饰的氨基位于残基1和赖氨酸15、27、47和51处。竞争数据显示，在残基27或47处掺入自旋标记降低了毒素对烟碱乙酰胆碱受体（AcChR）的亲和力，而在残基1或15处掺入减少了毒素对单克隆毒素特异性免疫球蛋白（M α 1）的亲和力。对每种衍生物进行经典和/或饱和转移电子自旋共振（ESR）分析，无论是在游离状态还是与AcChR或M α 1结合。所获得的数据表明了以下情况。在自由状态下，在残基1，15，47和51处掺入的氮氧自由基有它们自己的快速运动，而在残基27处掺入的氮氧自由基没有残留的运动性，反映了毒素的旋转。AcChR与毒素的结合减少了与Lys 47结合的氮氧自由基的运动。M α 1与毒素的结合固定了固定在残基1和15上的两个氮氧自由基。ESR光谱表明，赖氨酸27结合氮氧自由基保持固定后，无论是AcChR或M α 1的结合。在AcChR或M α 1结合后观察到的氮氧化物固定的变化与氮氧化物对水溶性顺磁性N2+ 1离子的可及性的变化很好地相关。标记的赖氨酸47毒素衍生物与乙酰胆碱受体的结合产生复杂的ESR信号，揭示了乙酰胆碱受体上两个毒素结合位点之间存在物理差异。所有的数据表明，乙酰胆碱受体和M α 1结合在两个地形不同的网站上的毒素表面。
Five derivatives of Naja nigricollis toxin alpha, spin-labeled on a single amino group, were prepared. The toxin derivatives were purified to homogeneity by ion-exchange and high-pressure liquid chromatographies. The modified amino groups are localized at residue 1 and lysines 15, 27, 47 and 51. Competition data show that incorporation of spin label at residues 27 or 47 reduces the affinity of the toxin for the nicotinic acetylcholine receptor (AcChR), while incorporation at residues 1 or 15 diminishes toxin affinity for a monoclonal toxin-specific immunoglobulin (M alpha 1). Classical and/or saturation transfer electron spin resonance (ESR) analysis was carried out on each derivative, either in the free state or bound to AcChR or M alpha 1. The data obtained give the following indications. In the free state, the nitroxides incorporated at residues 1, 15, 47 and 51 have their own rapid motion, while that at residue 27 had no residual mobility and reflects the toxin rotation. Binding of AcChR to the toxin reduces the motion of the nitroxide bound to Lys47. Binding of M alpha 1 to the toxin immobilizes the two nitroxides fixed on residues 1 and 15. ESR spectra show that Lys27-bound nitroxide remains immobilized upon binding of either AcChR or M alpha 1. The change in nitroxide immobilization observed upon AcChR or M alpha 1 binding correlates well with the variation of nitroxide accessibility to a water-soluble paramagnetic N2+i ion. Binding of the labeled Lys47 toxin derivative to AcChR yields a complex ESR signal, disclosing the existence of a physical difference between the two toxin binding sites on AcChR. All the data indicate that AcChR and M alpha 1 bind at two topographically distinct sites on the toxin surface.
可逆拮抗剂占据与乙酰胆碱受体功能之间的关系。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Sine,SM;Taylor,P
通讯作者：
Taylor,P