NMR PEPTIDE BINDING STUDIES OF PDZ DOMAIN OF CASK

木桶是一种蛋白质，已被确定在 神经元表面相关的细胞-细胞信号转导 蛋白质家族。Neuresin蛋白的胞质粒结构域相互作用 带有一个小的，84个残基的木桶PDZ结构域。当前项目是 目的是在分子水平上理解这种结合过程。 这一努力的核心是解决 PDZ结构域，这是我们用X射线结晶学所做的。与 蛋白质结构我们现在计划确定结合 与推定结合区域同源的多肽的构象 用多维异核核磁共振方法测定了纽瑞辛的含量。我们已经做出了 这一努力取得了重大进展。与克里斯博士合作 特纳和苏珊·S·波查普斯基博士我们已经记录了几个2DH--N-HSQC 未络合和多肽结合的PDZ结构域的光谱 已验证结合事件将显著扰乱酰胺 一些关键残基的化学位移。此外，我们还有 记录的3D1H，N-滤波NOESY-HSQC和TOCSY-HSQC谱 两种形式。这些光谱将对光谱有很大帮助 多肽的指认和结合方式的测定。

CASK is a protein which has been identified to be of importance in cell-cell signaling related to the neurexin neuronal cell surface protein family. The cytoplasmid domain of neurexin proteins interact with a small, 84 residue PDZ domain of CASK. The current project is aimed at understanding, at the molecular level, this binding process. Central to this effort is solving the three dimensional structure of the PDZ domain, which we have done by X-ray crystallography. With the protein structure in hand we now plan to determine the binding conformation of peptides homologous to the presumed binding region of the neurexins by multidimensional heteronuclear NMR. We have made significant progress on this effort. In collaboration with Dr. Chris Turner and Dr. Susan S. Pochapsky we have recorded several 2DH-"N-HSQC spectra on the uncomplexed and peptide bound PDZ domain and have verified that the binding event will significantly perturb amide chemical shifts of a number of key residues. Additionally, we have recorded 3D 1H,"N-filtered NOESY-HSQC and TOCSY-HSQC spectra of the two forms. These spectra will aid significantly in the spectral assignment and the determination of the binding mode of the peptide.