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Structure-Based Drug Design to Perturb Function of a tRNA-Modifying Enzyme by Active Site and Protein-Protein Interface Inhibition

  • Gerhard Klebe
Conference paper
Part of the NATO Science for Peace and Security Series A: Chemistry and Biology book series (NAPSA)

Abstract

Drug research increasingly focuses on the interference with protein-protein interface formation as attractive opportunity for therapeutic intervention. The tRNA-modifying enzyme Tgt, a putative drug target to fight Shigellosis, is only functionally active as a homodimer. To better understand the driving forces responsible for assembly and stability of the formed homodimer interface we embarked onto a computational and mutational analysis of the interface-forming residues. We also launched spiking ligands into the interface region to perturb contact formation. We controlled by non-degrading mass spectrometry the actual ratio of monomer-dimer equilibrium in solution and used crystal structure analysis to elucidate the geometrical changes resulting from the induced perturbance. A patch of four aromatic amino acids, embedded into a ring of hydrophobic residues and further stabilized by a network of H-bonds is essential for the dimer contact. Apart from the aromatic hot spot, the interface shows an extended loop-helix motif, which exhibits remarkable flexibility. In the destabilized mutant variants and the complexes with the spiking ligands, the loop-helix motif adopts deviating conformations in the interface region. This motivated us to follow a strategy to raise small molecule binders against this motif to mould the loop geometry in a conformation incompatible with the interface formation.

Keywords

Aromatic Amino Acid Dime Interface Monomeric State Binding Stoichiometry tRNA Molecule 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media Dordrecht 2015

Authors and Affiliations

  1. 1.Department of Pharmaceutical ChemistryUniversity of MarburgMarburgGermany

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