...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >NMR behavior of the aromatic protons of bovine neurophysin-I and its peptide complexes: implications for solution structure and for function.
【24h】

NMR behavior of the aromatic protons of bovine neurophysin-I and its peptide complexes: implications for solution structure and for function.

机译：牛神经物理学-I及其肽复合物的芳香族质子的NMR行为：对溶液结构和功能的影响。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The NMR behavior of the aromatic protons of bovine neurophysin-I and its complexes was interpreted with reference to the 2.8 A crystal structure of the dipeptide complex of bovine neurophysin-II and to mechanisms underlying the thermodynamic linkage between neurophysin dimerization and peptide binding. Large binding-induced shifts in the ring proton signals of Tyr-2 of ligand peptides (approximately 0.5 ppm upfield and approximately 0.35 ppm downfield at 25 degrees C for the 3,5- and 2,6-ring protons, respectively) were demonstrated. Consistent with the crystal structure, and in disagreement with conclusions by other investigators, evidence is presented indicating the absence of dipolar contact between Tyr-2 ring protons and protein Phe ring protons. The large binding-induced shifts are attributed to a strong influence of proximal neurophysin carbonyl and disulfide groups on the bound Tyr-2 ring, of potential importance in binding specificity. Resolution of the behavior of neurophysin Phe residues -22 and -35 and of their proton NOE contacts provided insights into the conformational changes associated with peptide binding and with dimerization. Within the amino domain of the protein, as evidenced by the behavior of interface residue Phe-35 and its NOE contacts, binding-induced changes in the subunit interface appeared to involve principally the junction between this interface region and the 3,10-helix that connects it to the binding site in the liganded state. By contrast, as judged by the NOE contacts of His-80, the corresponding interface participant of the carboxyl domain, peptide binding induced a marked decrease in side-chain mobility within the carboxyl domain segment of the interface. Interactions of Phe-22 with protons assigned to Ala-68, neither of which is an interface participant, were demonstrated to be markedly altered both by dimerization in the unliganded state and by peptide binding to the dimer. Since Phe-22 is adjacent to the peptide-binding site, the results collectively support a model in which conformational differences between unliganded monomer and dimer are important contributors to the preferential binding of peptide to the dimer and indicate that the amino and carboxyl domain segments of the interface, which are homologous, are affected differently by peptide binding.
机译：参照牛神经生理学-II的二肽复合物的2.8 A晶体结构以及神经生理学二聚化和肽结合之间的热力学联系的基础，来解释牛神经生理学-I及其复合物的芳香族质子的NMR行为。证明了配体肽的Tyr-2的环质子信号中的大的结合诱导的位移（对于3,5-和2,6-环质子在25℃下分别约0.5ppm的高场和约0.35ppm的低场）。与晶体结构一致，并且与其他研究者的结论不一致，证据表明Tyr-2环质子和蛋白Phe环质子之间不存在偶极接触。大的结合诱导的移位归因于近端神经物理羰基和二硫键基团对结合的Tyr-2环的强烈影响，这对结合特异性具有潜在的重要性。对神经物理Phe残基-22和-35残基及其质子NOE接触的行为的解析提供了对与肽结合和二聚化相关的构象变化的见解。如界面残基Phe-35及其NOE接触的行为所证明，在蛋白质的氨基结构域内，亚基界面的结合诱导变化似乎主要涉及该界面区域与3,10-螺旋之间的连接。将其连接到处于配体状态的结合位点。相反，通过His-80（羧基域的相应界面参与者）的NOE接触判断，肽结合导致界面羧基域区段内的侧链迁移率显着降低。 Phe-22与分配给Ala-68的质子之间的相互作用（都不是界面参与者）被证明在未配体状态下的二聚作用和与二聚体结合的肽都显着改变。由于Phe-22与肽结合位点相邻，因此该结果共同支持一个模型，其中未配体单体与二聚体之间的构象差异是肽与二聚体优先结合的重要因素，并表明该肽的氨基和羧基结构域片段同源的界面受肽结合的影响不同。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号