scholarly journals Intrinsic Thermodynamics of Protein-Ligand Binding by Isothermal Titration Calorimetry as Aid to Drug Design

Author(s):  
Vaida Paketurytė ◽  
Asta Zubrienė ◽  
John E. Ladbury ◽  
Daumantas Matulis
2017 ◽  
Author(s):  
Evgenii L. Kovrigin

ABSTRACTIn this paper, I theoretically analyzed ITC profiles for three-state equilibria involving ligand binding coupled to isomerization or dimerization transitions. Simulations demonstrate that the mechanisms where the free or ligand-bound protein undergoes dimerization (such that the ligand cannot bind to or dissociate from the dimer) produce very distinctive titration profiles. In contrast, profiles of the pre-existing equilibrium or induced-fit models cannot be distinguished from a simple two-state process, requiring data from additional techniques to positively identify these mechanisms.


2012 ◽  
Vol 30 (2) ◽  
pp. 169-183 ◽  
Author(s):  
Annemarie Beate Wöhri ◽  
Per Hillertz ◽  
Per-Olof Eriksson ◽  
Johan Meuller ◽  
Niek Dekker ◽  
...  

2013 ◽  
Vol 289 (3) ◽  
pp. 1377-1387 ◽  
Author(s):  
Jagdeep Kaur ◽  
Elena Olkhova ◽  
Viveka Nand Malviya ◽  
Ernst Grell ◽  
Hartmut Michel

Membrane proteins of the amino acid-polyamine-organocation (APC) superfamily transport amino acids and amines across membranes and play an important role in the regulation of cellular processes. We report the heterologous production of the LysP-related transporter STM2200 from Salmonella typhimurium in Escherichia coli, its purification, and functional characterization. STM2200 is assumed to be a proton-dependent APC transporter of l-lysine. The functional interaction between basic amino acids and STM2200 was investigated by thermoanalytical methods, i.e. differential scanning and isothermal titration calorimetry. Binding of l-lysine to STM2200 in its solubilized monomer form is entropy-driven. It is characterized by a dissociation constant of 40 μm at pH 5.9 and is highly selective; no evidence was found for the binding of l-arginine, l-ornithine, l-2,4-diaminobutyric acid, and l-alanine. d-Lysine is bound 45 times more weakly than its l-chiral form. We thus postulate that STM2200 functions as a specific transport protein. Based on the crystal structure of ApcT (Shaffer, P. L., Goehring, A., Shankaranarayanan, A., and Gouaux, E. (2009) Science 325, 1010–1014), a proton-dependent amino acid transporter of the APC superfamily, a homology model of STM2200 was created. Docking studies allowed identification of possible ligand binding sites. The resulting predictions indicated that Glu-222 and Arg-395 of STM2200 are markedly involved in ligand binding, whereas Lys-163 is suggested to be of structural and functional relevance. Selected variants of STM2200 where these three amino acid residues were substituted using single site-directed mutagenesis showed no evidence for l-lysine binding by isothermal titration calorimetry, which confirmed the predictions. Molecular aspects of the observed ligand specificity are discussed.


2010 ◽  
Vol 397 (4) ◽  
pp. 1042-1054 ◽  
Author(s):  
Bernhard Baum ◽  
Laveena Muley ◽  
Michael Smolinski ◽  
Andreas Heine ◽  
David Hangauer ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document