Modulation of PDZ domain-mediated protein-protein interactions

PDZ（PSD-95，Dlg，ZO-1）结构域通过介导蛋白质-蛋白质相互作用在细胞信号转导途径中发挥重要作用。天然肽配体结合到α-链和C-末端螺旋之间的脊中，其具有小分子结合位点的性质。在第一个资助期内鉴定了对几个PDZ结构域具有低至中等亲和力的抑制剂，并将相应物质类别的成员收集在PDZ库中。通过模拟化学循环对AF 6 PDZ结构域抑制剂的改进导致具有10至20微摩尔解离常数的化合物，破坏了细胞裂解物中的AF 6-Bcr相互作用。在第二个资助期，我们希望利用我们的研究结果，并专注于三个PDZ结构域（AF 6，DVL，Shank 3），旨在了解相应蛋白质的生物学。将使用斑马鱼模型在细胞生物学和体内实验中进一步研究AF 6 PDZ结构域抑制剂（与Ted Allison，阿尔伯塔合作）。将与TP 9（Birchmeier，von Kries）合作研究Dishevelled（DVL 9）抑制剂对Wnt信号通路的影响。Shank 3在突触后密度中的作用将与柏林Neurocure项目的Dietmar Schmitz一起研究。通过计算方法鉴定PDZ结构域的选择性模式将有助于进一步开发更特异的抑制剂。特定的配体将通过NMR光谱研究、计算机辅助配体设计和药物化学循环产生。作为一个模型病例，我们将开发特异性配体与CAL结合，但不与NHERF结合，这两种蛋白质在囊性纤维化中起着至关重要的作用。

PDZ (PSD-95, Dlg, ZO-1) domains play important roles in cellular signalling pathways by mediating protein-protein interactions. The native peptide ligands bind into a ridge between a ß-strand and the C-terminal helix which has properties of a small-molecule binding site. Inhibitors with low to medium affinity for several PDZ domains were identified in the first funding period and members of the respective substance classes were collected in a PDZ-library . Improvements of the AF6 PDZ domain Inhibitors by modelling-chemistry cycles resulted in compounds with ten to twenty micromolar dissociation constants, disrupting the AF6-Bcr interaction in cell lysates. In the second funding period we want to exploit our results and focus on three PDZ domains (AF6, DVL, Shank3), aiming at an understanding of the biology of the respective proteins. The AF6 PDZ domain inhibitors will be investigated further in cell biological and in vivo experiments using a zebra fish model (collaboration with Ted Allison, Alberta). Inhibitors of Dishevelled (DVL9) will be investigated with respect their effects on the Wnt signalling pathway in collaboration with TP 9 (Birchmeier, von Kries). The role of the Shank3 in the postsynaptic density will be investigated together with Dietmar Schmitz, of the Berlin Neurocure program. The identification of selectivity patterns of PDZ domains by computational methods will help to further develop even more specific inhibitors. Specific ligands will be generated by cycles of NMR-spectroscopic investigations, Computer assisted ligand design, and medicinal chemistry. As a model case we will develop specific ligands binding to CAL but not to NHERF, two proteins playing crucial roles in cystic fibrosis.