• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Biomolecular Structure and Dynamics >Interactions of calmodulin with death-associated protein kinase peptides: Experimental and modeling studies
【24h】

Interactions of calmodulin with death-associated protein kinase peptides: Experimental and modeling studies

机译：钙调蛋白与死亡相关的蛋白激酶肽的相互作用：实验和模型研究

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

We have studied the interactions between calmodulin (CaM) and three target peptides from the death-associated protein kinase (DAPK) protein family using both experimental and modeling methods, aimed at determining the details of the underlying biological regulation mechanisms. Experimentally, calorimetric binding free energies were determined for the complexes of CaM with peptides representing the DAPK2 wild-type and S308D mutant, as well as DAPK1. The observed affinity of CaM was very similar for all three studied peptides. The DAPK2 and DAPK1 peptides differ significantly in sequence and total charge, while the DAPK2 S308D mutant is designed to model the effects of DAPK2 Ser308 phosphorylation. The crystal structure of the CaM-DAPK2 S308D mutant peptide is also reported. The structures of CaM-DAPK peptide complexes present a mode of CaM-kinase interaction, in which bulky hydrophobic residues at positions 10 and 14 are both bound to the same hydrophobic cleft. To explain the microscopic effects underlying these interactions, we performed free energy calculations based on the approximate MM-PBSA approach. For these highly charged systems, standard MM-PBSA calculations did not yield satisfactory results. We proposed a rational modification of the approach which led to reasonable predictions of binding free energies. All three complexes are strongly stabilized by two effects: electrostatic interactions and buried surface area. The strong favorable interactions are to a large part compensated by unfavorable entropic terms, in which vibrational entropy is the largest contributor. The electrostatic component of the binding free energy followed the trend of the overall peptide charge, with strongest interactions for DAPK1 and weakest for the DAPK2 mutant. The electrostatics was dominated by interactions of the positively charged residues of the peptide with the negatively charged residues of CaM. The nonpolar binding free energy was comparable for all three peptides, the largest contribution coming from the Trp305. About two-thirds of the buried surface area corresponds to nonpolar residues, showing that hydrophobic interactions play an important role in these CaM-peptide complexes. The simulation results agree with the experimental data in predicting a small effect of the S308D mutation on CaM interactions with DAPK2, suggesting that this mutation is not a good model for the S308 phosphorylation.
机译：我们已经使用实验和建模方法研究了钙调蛋白（CaM）与来自死亡相关蛋白激酶（DAPK）蛋白家族的三个靶肽之间的相互作用，旨在确定潜在的生物学调控机制的细节。实验上，针对CaM与代表DAPK2野生型和S308D突变体以及DAPK1的肽的复合物，确定了量热结合自由能。对于所有三种研究的肽，观察到的CaM亲和力都非常相似。 DAPK2和DAPK1肽的序列和总电荷明显不同，而DAPK2 S308D突变体旨在模拟DAPK2 Ser308磷酸化的作用。还报道了CaM-DAPK2 S308D突变肽的晶体结构。 CaM-DAPK肽复合物的结构呈现CaM激酶相互作用的一种模式，其中在位置10和14的大块疏水残基都结合到同一疏水裂缝上。为了解释这些相互作用的微观影响，我们基于近似的MM-PBSA方法进行了自由能计算。对于这些高电荷系统，标准的MM-PBSA计算无法产生令人满意的结果。我们提出了对该方法的合理修改，从而导致对结合自由能的合理预测。这三种复合物均通过以下两种作用得到强烈稳定：静电相互作用和掩埋表面积。强烈的有利相互作用在很大程度上被不利的熵项所补偿，在熵项中，振动熵是最大的贡献者。结合自由能的静电成分遵循总肽电荷的趋势，其中DAPK1的相互作用最强，而DAPK2突变体的相互作用最弱。静电主要受肽带正电荷的残基与CaM带负电荷的残基的相互作用的影响。非极性结合自由能对于所有三种肽都是可比的，最大的贡献来自于Trp305。约三分之二的掩埋表面积对应于非极性残基，表明疏水相互作用在这些CaM肽复合物中起重要作用。模拟结果与预测S308D突变对CaM与DAPK2相互作用的小影响的实验数据吻合，表明该突变不是S308磷酸化的良好模型。

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