title: NMR characterization of weak interactions between RhoGDI2 and fragment screening hits.
abstract: The delineation of intrinsically weak interactions between novel targets and fragment screening hits has long limited the pace of hit-to-lead evolution. Rho guanine-nucleotide dissociation inhibitor 2 (RhoGDI2) is a novel target that lacks any chemical probes for the treatment of tumor metastasis.
  
  
  
  Protein-observed and ligand-observed NMR spectroscopy was used to characterize the weak interactions between RhoGDI2 and fragment screening hits.
  
  
  
  We identified three hits of RhoGDI2 using streamlined NMR fragment-based screening. The binding site residues were assigned using non-uniformly sampled Cα- and Hα-based three dimensional NMR spectra. The molecular docking to the proposed geranylgeranyl binding pocket of RhoGDI2 was guided by NMR restraints of chemical shift perturbations and ligand-observed transferred paramagnetic relaxation enhancement. We further validated the weak RhoGDI2-hit interactions using mutagenesis and structure-affinity analysis.
  
  
  
  Weak interactions between RhoGDI2 and fragment screening hits were delineated using an integrated NMR approach.
  
  
  
  Binders to RhoGDI2 as a potential anti-cancer target have been first reported, and their weak interactions were depicted using NMR spectroscopy. Our work highlights the powerfulness and the versatility of the integrative NMR techniques to provide valuable structural insight into the intrinsically weak interactions between RhoGDI2 and the fragment screening hits, which could hardly be conceived using other biochemical techniques.
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Jiuyang
authors.initials: J
authors.lastname: Liu
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Gao
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Fudong
authors.initials: F
authors.lastname: Li
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Rongsheng
authors.initials: R
authors.lastname: Ma
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Qingtao
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Aidong
authors.initials: A
authors.lastname: Wang
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Jihui
authors.initials: J
authors.lastname: Wu
authors.affiliation: Hefei National Laboratory for Physical Science at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China. Electronic address: kruan@ustc.edu.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Ruan
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D006801:Humans; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D010446:Peptide Fragments / Q000378:metabolism*; D015203:Reproducibility of Results; D054852:Small Molecule Libraries / Q000378:metabolism; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008024:Ligands; D010446:Peptide Fragments; D054852:Small Molecule Libraries; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta
keywords: Fragment-based lead discovery; Non-uniform sampling NMR; Posttranslational modification; Rho guanine-nucleotide dissociation inhibitor 2; Transferred paramagnetic relaxation enhancement