Towards understanding structural and dynamical determinants of G protein inhibition - rational design of novel subtype specific G-protein inhibitors

选择性抑制G蛋白，从而抑制G蛋白介导的信号是一种非常有效的药理学方法。因此，人们致力于开发核苷酸状态选择性抑制剂，以抑制非活性鸟苷二磷酸（GDP）结合的异源三聚体和活性鸟苷三磷酸（GTP）结合的Galpha或gβ - γ二聚体。迄今为止，在全细胞中具有活性的Galpha亚基抑制剂很少有报道。通过核磁共振波谱和分子动力学模拟鉴定小分子BIM和gq特异性沉积肽FR900359及其衍生化合物（P1-3）抑制G蛋白的结构和动力学决定因素是本项目的一个核心问题。因此，将利用各种核磁共振技术在各种条件下研究分离的G蛋白（P2）在溶液和固体状态下有和没有结合抑制剂的构象。从这些研究中获得的知识以及生物学和药理学活性数据（P5, P6）和核磁共振衍生的抑制剂解离常数（本项目）将指导计算机辅助设计新型亚型特异性G蛋白抑制剂，以便抑制每种G蛋白亚型的G蛋白信号传导。对接和MD模拟将用于开发和预先选择可能的命中结构，这些结构将分别在P1， P2和P3中合成。

Selective inhibition of G proteins, thus suppressing G protein-mediated signaling is an extremely powerful, pharmacological approach. Consequently, efforts have been undertaken to develop nucleotide-state-selective inhibitors for both, inactive guanosine diphosphate (GDP)-bound heterotrimers and active guanosine triphosphate (GTP)-bound Galpha or Gbeta-gamma dimers. To date very few Galpha subunit inhibitors with activity in whole cells have been reported. Identification of structural and dynamical determinants of G protein inhibition by the small molecule BIM and the Gq-specific depsipeptide FR900359 and compounds derived thereof (P1-3) through NMR spectroscopy and molecular dynamic simulations is one central issue of this project. Therefore, conformation of isolated G proteins (P2) with and without bound inhibitors in solution as well as in the solid state will be studied under various conditions utilizing various NMR techniques. The knowledge gained from these investigations accompanied with biological and pharmacological activity data (P5, P6) and NMR-derived inhibitor dissociation constants (this project) will guide the computer-assisted design of novel, subtype specific G protein inhibitors, in order to permit suppression of G protein signaling of each individual G protein subtype. Docking and MD simulations will be utilized to develop and preselect possible hit structures, which will be synthesized in P1, P2, and P3, respectively.