保守的柔性接头实现的最佳亲和力增强控制MdmX中的p53模拟。
Optimal Affinity Enhancement by a Conserved Flexible Linker Controls p53 Mimicry in MdmX.
作者信息
Borcherds Wade, Becker Andreas, Chen Lihong, Chen Jiandong, Chemes Lucía B, Daughdrill Gary W
机构信息
Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida; Center for Drug Discovery and Innovation, University of South Florida, Tampa, Florida.
Drug Discovery Department, Moffitt Cancer Center, Tampa, Florida.
出版信息
Biophys J. 2017 May 23;112(10):2038-2042. doi: 10.1016/j.bpj.2017.04.017. Epub 2017 May 6.
MdmX contains an intramolecular binding motif that mimics the binding of the p53 tumor suppressor. This intramolecular binding motif is connected to the p53 binding domain of MdmX by a conserved flexible linker that is 85 residues long. The sequence of this flexible linker has an identity of 51% based on multiple protein sequence alignments of 52 MdmX homologs. We used polymer statistics to estimate a global K value for p53 binding to MdmX in the presence of the flexible linker and the intramolecular binding motif by assuming the flexible linker behaves as a wormlike chain. The global K estimated from the wormlike chain modeling was nearly identical to the value measured using isothermal titration calorimetry. According to our calculations and measurements, the intramolecular binding motif reduces the apparent affinity of p53 for MdmX by a factor of 400. This study promotes a more quantitative understanding of the role that flexible linkers play in intramolecular binding and provides valuable information to further studies of cellular inhibition of the p53/MdmX interaction.
MdmX含有一个模拟p53肿瘤抑制因子结合的分子内结合基序。这个分子内结合基序通过一个由85个残基组成的保守柔性接头与MdmX的p53结合结构域相连。基于52个MdmX同源物的多蛋白序列比对，这个柔性接头的序列一致性为51%。我们利用聚合物统计学方法，通过假设柔性接头表现为蠕虫状链，来估计在存在柔性接头和分子内结合基序的情况下p53与MdmX结合的全局K值。从蠕虫状链模型估计的全局K值与使用等温滴定量热法测量的值几乎相同。根据我们的计算和测量，分子内结合基序使p53对MdmX的表观亲和力降低了400倍。这项研究促进了对柔性接头在分子内结合中所起作用的更定量理解，并为进一步研究细胞对p53/MdmX相互作用的抑制提供了有价值的信息。
Zotero 插件