Lee W, Moore C H, Watt D D, Krishna N R
Department of Biochemistry, University of Alabama at Birmingham 39294.
Eur J Biochem. 1994 Jan 15;219(1-2):89-95. doi: 10.1111/j.1432-1033.1994.tb19918.x.
The solution structure of the CsE-v3 neurotoxin from the venom of the North American scorpion Centruroides sculpturatus Ewing (CsE) has been determined by a hybrid refinement procedure that employed distance geometry and dynamical simulated annealing. Distance constraints deduced from the nuclear Overhauser effect spectroscopy data and torsion angle constraints deduced from the vicinal coupling constant data were used in the refinement procedure. A family of simulated annealing structures that showed no constraint violations was generated. The energy-minimized average structure exhibited root-mean-square deviations of 0.121 nm for the backbone and 0.182 nm for all atoms, with respect to this family. These studies confirm the previously qualitative NMR findings about the secondary structural features, viz. the presence of a short alpha-helix composed of residues 23-31 and an antiparallel beta-sheet composed of the strands of residues 1-5, 45-50 and 36-42. A cluster of aromatic ring systems is located on one side of the protein. The solution and crystal structures have similar overall features, but show some minor differences.
已通过采用距离几何和动态模拟退火的混合优化程序确定了来自北美雕刻毒蝎（Centruroides sculpturatus Ewing，简称CsE）毒液中的CsE-v3神经毒素的溶液结构。在优化过程中使用了从核Overhauser效应光谱数据推导的距离约束和从邻位耦合常数数据推导的扭转角约束。生成了一组无约束违反的模拟退火结构。相对于该组结构，能量最小化的平均结构主链的均方根偏差为0.121 nm，所有原子的均方根偏差为0.182 nm。这些研究证实了先前关于二级结构特征的定性核磁共振研究结果，即存在由23-31位残基组成的短α螺旋以及由1-5、45-50和36-42位残基链组成的反平行β折叠。一组芳香环系统位于蛋白质的一侧。溶液结构和晶体结构具有相似的整体特征，但也存在一些细微差异。
