Tsetlin V I, Karlsson E, Pluzhnikov K A, Arseniev A S, Surin A M, Kondakov V V, Bystrov V F, Ivanov V T
Toxicon. 1982;20(1):83-93. doi: 10.1016/0041-0101(82)90171-4.
Binding of neurotoxin II Naja naja oxiana derivatives containing one spin label at various positions (Leu 1, Glu 2, Lys 15, Lys 25, Lys 26, His 31, Lys 44 and Lys 46) to purified solubilized acetylcholine receptor protein (AchR) from Torpedo marmorata was studied by EPR techniques. AchR interaction with several dansylated neurotoxin II derivatives was followed by difference fluorescence spectroscopy. A series of neurotoxin II p-azidobenzoyl derivatives were prepared and in three of them modified lysine residues were identified. In combination, spectroscopic data and photolabeling implicate a considerable area of the neurotoxin in association with AchR. Rigidity of the neurotoxin II conformation allowed to regard its binding surface as a mould of the AchR corresponding site and to estimate the minimal size of the latter. Conformation of the long-chain neurotoxins and their binding to AchR are briefly discussed basing on the 1H and 19F NMR studies of neurotoxin I Naja naja oxiana, toxin 3 Naja naja siamensis and its acetylated or trifluoroacetylated derivatives, as well as on Achr interaction with the derivatives spin labeled at Lys 27 and His 71.
利用电子顺磁共振技术研究了含一个自旋标记且自旋标记位于不同位置（亮氨酸1、谷氨酸2、赖氨酸15、赖氨酸25、赖氨酸26、组氨酸31、赖氨酸44和赖氨酸46）的眼镜王蛇神经毒素II衍生物与从电鳐纯化的可溶性乙酰胆碱受体蛋白（AchR）的结合情况。通过差示荧光光谱法跟踪AchR与几种丹磺酰化神经毒素II衍生物的相互作用。制备了一系列神经毒素II对叠氮苯甲酰衍生物，并鉴定出其中三种衍生物中经修饰的赖氨酸残基。光谱数据和光标记相结合表明，神经毒素与AchR结合的区域相当大。神经毒素II构象的刚性使其结合表面可被视为AchR相应位点的模板，并据此估计了后者的最小尺寸。基于对眼镜王蛇神经毒素I、眼镜王蛇毒素3及其乙酰化或三氟乙酰化衍生物的1H和19F核磁共振研究，以及AchR与在赖氨酸27和组氨酸71处自旋标记的衍生物的相互作用，简要讨论了长链神经毒素的构象及其与AchR的结合。
