Analysis of side-chain conformational distributions in neutrophil peptide-5 NMR structures.
Analysis of side-chain conformational distributions in neutrophil peptide-5 NMR structures.
复制标题
中性粒细胞肽 5 NMR 结构中侧链构象分布的分析。
DOI：
10.1002/bip.360291412
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发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
Pardi,A
中科院分区：
文献类型：
--
作者：
Kominos,D;Bassolino,DA;Levy,RM;Pardi,A
已经分析了抗菌肽--神经肽-5（NP-5）的侧链构象，其结构是使用距离几何算法从NMR推导的距离约束独立生成的。核磁共振结构中的侧链和肽二面角分布与从高分辨率蛋白质晶体结构数据库构建的那些进行了比较。溶液中NP-5的侧链构象偏好与晶体结构数据库中观察到的显著不同。这些结果表明，NP-5的许多残基的侧链构象是相当无序的。构象分布的宽度和表面可及性之间没有相关性，这表明这种无序可能是由于从核磁共振数据中提取的结构信息的限制，而不是分子运动。然而，它也被观察到，构象紊乱的程度是只有弱相关的核Overhauser增强到一个给定的侧链的数量。可能的原因进行了讨论。这些结构的分子力学精修没有显著改变侧链群体。在NP-5距离几何结构中，观察到关于肽键和二硫键的旋转的异常宽的分布，这通过改进得到了改善。在高分辨率晶体数据库中观察到的二硫键中心二面角的高度有序性表明，蛋白质中围绕该键的旋转由局部势决定。
The side‐chain conformations have been analyzed in the antimicrobial peptide, Neutrophil Peptide‐5(NP‐5), whose structure was independently generated from nmr‐derived distance constraints using a distance geometry algorithm. The side‐chain and peptide dihedral angle distributions in the nmr structures were compared with those constructed from a data base of high‐resolution protein crystal structures. The side‐chain conformational preferences for NP‐5 in solution are significantly different from those observed in the crystal structure data base. These results indicate that the side‐chain conformations are quite disordered for many of the residues of NP‐5. The absence of a correlation between the width of the conformational distribution and surface accessibility suggests that the disorder may be due to limitations in the structural information extracted from the nmr data rather than to molecular motion. However, it is also observed that the degree of conformational disorder is only weakly correlated with the number of nuclear Overhauser enhancements to a given side chain. Possible reasons for this are discussed. Molecular mechanics refinement of these structures did not significantly change the side‐chain populations. Anomolously wide distributions are observed for rotations about the peptide bonds and the disulfide bonds in the NP‐5 distance geometry structures, which are improved by the refinement. The very high degree of order observed for the central dihedral angle of the disulfide bond in the high‐resolution crystal data base suggests that the rotation about this bond in proteins is determined by the local potential.