High-Precision Isothermal Titration Calorimetry with Automated Peak-Shape Analysis
- 24 April 2012
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 84 (11), 5066-5073
- https://doi.org/10.1021/ac3007522
Abstract
Isothermal titration calorimetry (ITC) is a powerful classical method that enables researchers in many fields to study the thermodynamics of molecular interactions. Primary ITC data comprise the temporal evolution of differential power reporting the heat of reaction during a series of injections of aliquots of a reactant into a sample cell. By integration of each injection peak, an isotherm can be constructed of total changes in enthalpy as a function of changes in solution composition, which is rich in thermodynamic information on the reaction. However, the signals from the injection peaks are superimposed by the stochastically varying time-course of the instrumental baseline power, limiting the precision of ITC isotherms. Here, we describe a method for automated peak assignment based on peak-shape analysis via singular value decomposition in combination with detailed least-squares modeling of local pre- and postinjection baselines. This approach can effectively filter out contributions of short-term noise and adventitious events in the power trace. This method also provides, for the first time, statistical error estimates for the individual isotherm data points. In turn, this results in improved detection limits for high-affinity or low-enthalpy binding reactions and significantly higher precision of the derived thermodynamic parameters.Keywords
This publication has 40 references indexed in Scilit:
- Measurement and Theory of Hydrogen Bonding Contribution to Isosteric DNA Base PairsJournal of the American Chemical Society, 2012
- Comparison of Several Methods of Chromatographic Baseline Removal with a New Approach Based on Quantile RegressionChromatographia, 2011
- Higher throughput calorimetry: opportunities, approaches and challengesCurrent Opinion in Structural Biology, 2010
- Structural and Thermodynamic Characterization of the TYK2 and JAK3 Kinase Domains in Complex with CP-690550 and CMP-6Journal of Molecular Biology, 2010
- Some statistical properties of differencing schemes for baseline correction of sedimentation velocity dataAnalytical Biochemistry, 2010
- A general-purpose baseline estimation algorithm for spectroscopic dataAnalytica Chimica Acta, 2010
- Analysis of Cooperativity by Isothermal Titration CalorimetryInternational Journal of Molecular Sciences, 2009
- A cationic host displaying positive cooperativity in waterProceedings of the National Academy of Sciences of the United States of America, 2007
- Studying multisite binary and ternary protein interactions by global analysis of isothermal titration calorimetry data in SEDPHAT: Application to adaptor protein complexes in cell signalingProtein Science, 2007
- Metal-binding properties of human erythrocyte carbonic anhydrasesBiochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects, 1964