NMR solution structure of type II human cellular retinoic acid binding protein: implications for ligand binding.
NMR solution structure of type II human cellular retinoic acid binding protein: implications for ligand binding.
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II 型人细胞视黄酸结合蛋白的 NMR 溶液结构：对配体结合的影响。
DOI：
10.1021/bi9808924
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Yan,H
中科院分区：
文献类型：
--
作者：
Wang,L;Li,Y;Abildgaard,F;Markley,JL;Yan,H
人脱辅基细胞视黄酸结合蛋白II（apo-CRABPII）在pH 7.3的溶液中的结构已被确定的NMR光谱。通过多核多维核磁共振波谱法建立了apo-CRABP Ⅱ的1H、13 C和15 N共振的顺序归属。apo-CRABPII的解决方案结构来自2382实验NMR限制使用混合距离几何模拟退火协议。25个代表结构的精细构象异构体的系综的均方根偏差分别为0.54 ± 0.18和0.92 ± 0.20 Ω，对于所有残基的骨架原子和所有重原子，除了Ala 32 −Pro39和Thr 57 − Glu 62，它们处于无序区域。apo-CRABPII的溶液结构类似于holo-CRABPII的晶体结构[Kleywegt，G. J.，Bergfors，T.，Senn，H.，Le Motte，P.，Gsell，B.，Shudo，K.，和Jones，T. A.（1994）结构2，1241 - 1258]除了配体入口，其在脱辅基蛋白中充分扩大以易于接近视黄酸。apo-CRABPII的配体入口相对于holo-CRABPII的配体入口的扩大主要是由于三个结构元件的协同构象变化，即第二螺旋，βC−βD环和βE−βF环。此外，apo-CRABP Ⅱ的配体结合口袋显示出动态紊乱的证据;在构成这个口袋的21个残基中，16个残基在最小水饱和或失相条件下记录的二维1H − 15 N HSQC光谱中具有弱的或不可检测的交叉峰。Apo-CRABPI II在溶液中主要是单体，没有证据表明在apo-CRABPI的晶体结构中显示二聚体结构，其被认为是配体进入的先决条件[Thompson，J.R.，布拉特，J.M.，和Banaszak，L. J.（1995）J. Mol. 252，433 - 446]。因此，视黄酸进入所需的配体入口的加宽似乎是单体apo-CRABPII的性质。
The structure of human apo-cellular retinoic acid binding protein II (apo-CRABPII) in solution at pH 7.3 has been determined by NMR spectroscopy. The sequential assignments of the1H,13C, and15N resonances of apo-CRABPII were established by multinuclear, multidimensional NMR spectroscopy. The solution structure of apo-CRABPII was derived from 2382 experimental NMR restraints using a hybrid distance geometry-simulated annealing protocol. The root-mean-square deviation of the ensemble of 25 refined conformers that represent the structure from the mean coordinate set derived from them was 0.54 ± 0.18 and 0.92 ± 0.20 Å for the backbone atoms and all heavy atoms, respectively, of all residues except Ala32−Pro39 and Thr57−Glu62, which are in disordered regions. The solution structure of apo-CRABPII is similar to the crystal structure of holo-CRABPII [Kleywegt, G. J., Bergfors, T., Senn, H., Le Motte, P., Gsell, B., Shudo, K., and Jones, T. A. (1994)Structure 2, 1241−1258] except the ligand entrance, which is sufficiently enlarged in the apoprotein to be readily accessible to retinoic acid. The enlargement of the ligand entrance of apo-CRABPII relative to that of holo-CRABPII is due mainly to a concerted conformational change in three structural elements, namely, the second helix, the βC−βD loop, and the βE−βF loop. Furthermore, the ligand-binding pocket of apo-CRABPII showed evidence of dynamic disorder; among the 21 residues that constitute this pocket, 16 residues had weak or no detectable cross-peaks in the two-dimensional1H−15N HSQC spectrum recorded under conditions of minimal water saturation or dephasing. Apo-CRABPII is largely monomeric in solution, with no evidence for the dimeric structure shown in the crystal structure of apo-CRABPI which was suggested to be a prerequisite for ligand entry [Thompson, J. R., Bratt, J. M., and Banaszak, L. J. (1995)J. Mol. Biol. 252, 433−446]. Thus, the widening of the ligand entrance required for entry of retinoic acid appears to be a property of monomeric apo-CRABPII.