Isothermal titration calorimetry for drug design: Precision of the enthalpy and binding constant measurements and comparison of the instruments

Vaida Linkuvienė; Georg Krainer; Wen-Yih Chen; Daumantas Matulis

doi:10.1016/j.ab.2016.10.005

Isothermal titration calorimetry for drug design: Precision of the enthalpy and binding constant measurements and comparison of the instruments

Anal Biochem. 2016 Dec 15:515:61-64. doi: 10.1016/j.ab.2016.10.005. Epub 2016 Oct 4.

Authors

Vaida Linkuvienė¹, Georg Krainer², Wen-Yih Chen³, Daumantas Matulis⁴

Affiliations

¹ Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio 7, Vilnius, LT, 10257, Lithuania.
² Department of Molecular Biophysics, University of Kaiserslautern, Kaiserslautern, Germany; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany.
³ Department of Chemical and Materials Engineering, National Central University, Taiwan.
⁴ Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio 7, Vilnius, LT, 10257, Lithuania. Electronic address: matulis@ibt.lt.

PMID: 27717855
DOI: 10.1016/j.ab.2016.10.005

Abstract

Isothermal titration calorimetry (ITC) is one of the most robust label- and immobilization-free techniques used to measure protein - small molecule interactions in drug design for the simultaneous determination of the binding affinity (ΔG) and the enthalpy (ΔH), both of which are important parameters for structure-thermodynamics correlations. It is important to evaluate the precision of the method and of various ITC instrument models by performing a single well-characterized reaction. The binding between carbonic anhydrase II and acetazolamide was measured by four ITC instruments - PEAQ-ITC, iTC200, VP-ITC, and MCS-ITC and the standard deviation of ΔG and ΔH was determined. Furthermore, the limit of an approach to reduce the protein concentration was studied for a high-affinity reaction (K_d = 0.3 nM), too tight to be measured by direct (non-displacement) ITC. Chemical validation of the enthalpy measurements is discussed.

Keywords: Acetazolamide; Calorimeter; Carbonic anhydrase; Enthalpy; Isothermal titration calorimetry (ITC); Nitpic and Sedphat; Protein – ligand binding.

MeSH terms

Calorimetry / methods
Carbonic Anhydrase II / chemistry*
Drug Design*
Humans
Thermodynamics*

Substances

Carbonic Anhydrase II