Three-dimensional structure of a protein from scorpion venom: a new structural class of neurotoxins.
Three-dimensional structure of a protein from scorpion venom: a new structural class of neurotoxins.
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DOI：
10.1073/pnas.77.11.6496
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发表时间：
1980-11
影响因子：
11.1
通讯作者：
J. Fontecilla-Camps;R. Almassy;F. L. Suddath;D. Watt;C. Bugg
中科院分区：
文献类型：
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作者：
J. Fontecilla-Camps;R. Almassy;F. L. Suddath;D. Watt;C. Bugg
测定了蝎蝎毒素变体-3的三维晶体结构。通过使用K2 PtCl 4和K2 IrCl 6衍生物获得相。最突出的二级结构特征是α-螺旋的两个半圈和平行于α-螺旋的反平行β-折叠的三链延伸。螺旋通过两个二硫桥连接到β折叠的中间链;第三个二硫桥位于附近。有几个环从这个致密的二级结构核心延伸出来。最大的环通过第四个二硫键连接到分子的COOH末端。分子的整体形状类似于右手的拳头：α-螺旋沿着拳头的指关节; β-折叠沿着手指的第二和第三关节;拇指由两个短环限定，所述短环由残基16-21和残基41-46组成;腕关节对应于残基52-65的COOH-末端延伸和由残基5-14组成的环;小指的第二关节靠近分子的NH 2末端。在拳头模型中，α-碳骨架显示出一个大的平面，该平面沿着手指的第二关节和手的脚跟。蝎神经毒素中的几个保守残基聚集在该表面上，这可能在蝎毒素与可兴奋膜钠通道的相互作用中发挥作用。
The three-dimensional crystal structure of variant-3 toxin from the scorpion Centruroides sculpturatus Ewing has been determined at 3 A resolution. Phases were obtained by use of K2PtCl4 and K2IrCl6 derivatives. The most prominent secondary structural features are two and a half turns of alpha-helix and a three-strand stretch of antiparallel beta-sheet, which runs parallel to the alpha-helix. The helix is connected to the middle strand of the beta-sheet by two disulfide bridges; a third disulfide bridge is located nearby. Several loops extend out of this dense core of secondary structure. The largest loop is joined to the COOH terminus of the molecule by the fourth disulfide bridge. The overall shape of the molecule resembles a right-hand fist: the alpha-helix runs along the knuckles of the fist; the beta-sheet lies along the second and third joints of the fingers; the thumb is defined by two short loops that are composed of residues 16-21 and residues 41-46; the wrist corresponds to the COOH-terminal stretch of residues 52-65 and a loop composed of residues 5-14; and the second joint of the little finger is near the NH2 terminus of the molecule. The alpha-carbon backbone displays a large flat surface that lies along the second joints of the fingers and the heel of the hand in the fist model. Several of the conserved residues in the scorpion neurotoxins are clustered on this surface, which may play a role in interactions of scorpion toxins with sodium channels of excitable membranes.