3-DIMENSIONAL STRUCTURE OF RABBIT LIVER [CD7]METALLOTHIONEIN-2A IN AQUEOUS-SOLUTION DETERMINED BY NUCLEAR MAGNETIC-RESONANCE
3-DIMENSIONAL STRUCTURE OF RABBIT LIVER [CD7]METALLOTHIONEIN-2A IN AQUEOUS-SOLUTION DETERMINED BY NUCLEAR MAGNETIC-RESONANCE
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DOI：
10.1016/0022-2836(88)90644-4
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发表时间：
1988-06-05
影响因子：
5.6
通讯作者：
WUTHRICH, K
中科院分区：
文献类型：
--
作者：
ARSENIEV, A;SCHULTZE, P;WUTHRICH, K
在先前的工作中，测定了在水溶液中来自兔肝的重构[113 Cd 7]金属硫蛋白-2制剂的主要蛋白质种类中的金属-多肽配位键，发现二级多肽结构包含几个半转角和310螺旋片段，并且初步表征了β-CD-1中的总多肽骨架折叠。域，所述域包含三金属簇，并且α-域包含四个金属簇，得到。使用一个新的，更广泛的一组核磁共振数据，这些早期的结构得到了改进，通过新的结构计算。新的实验数据包括距离约束的核Overhauser效应的测量，二面角的约束来自耦合常数和核Overhauser效应。结构计算用DISMAN程序进行。由于不能获得关于两个结构域相对于彼此的取向的信息，因此分别对α-β结构域进行结构计算。域和β-域在具有输入约束的最小残余违反的20个结构之间的成对均方根距离的平均值为2.9埃。对于β-域和1.4.ANG。对于α-结构域（1. = 0.1 nm）。多肽折叠的总体手性对于β-环己基是右旋的。域和左手的α-域对于每七个金属离子的本地手性的协调的四个半胱氨酰S. γ。原子的定义是明确的。这两个域的改进结构显示出先前注意到的差异相对于最近公布的大鼠肝脏金属硫蛋白-2a的晶体结构。
In previous work the metal-polypeptide co-ordinative bonds in the major protein species of a reconstituted [113Cd7]metallothionein-2 preparation from rabbit liver in aqueous solution were determined, the secondary polypeptide structure was found to contain several half-turns and 310-helical segments, and a preliminary characterization of the overall polypeptide backbone fold in the .beta.-domain containing the three-metal cluster, and the .alpha.-domain containing the four-metal cluster, was obtained. Using a new, more extensive set of nuclear magnetic resonance data these earlier structures were improved by new structure calculations. The new experimental data consist of distance constraints from measurements of nuclear Overhauser effects, and dihedral angle constraints derived from both coupling constants and nuclear Overhauser effects. The structure calculations were performed with the program DISMAN. Since no information on the orientation of the two domains relative to each other could be obtained, the structure calculations wree performed separately for the .alpha.-domain and the .beta.-domain. The average of the pairwise root-mean-square distances among the 20 structures with the least residual violations of input constraints was 2.9 .ANG. for the .beta.-domain and 1.4 .ANG. for the .alpha.-domain (1 .ANG. = 0.1 nm). The overall chirality of the polypeptide fold is right-handed for the .beta.-domain and left-handed for the .alpha.-domain. For each of the seven metal ions the local chirality of the co-ordination of the four cysteinyl S.gamma. atoms is clearly defined. The improved structures of both domains show the previously noted differences relative to the recently published crystal structure of metallothionein-2a from rat liver.