Lee D Hansen1, Mark K Transtrum2, Colette Quinn3, Neil Demarse4. 1. Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA. Electronic address: lee_hansen@byu.edu. 2. Department of Physics & Astronomy, Brigham Young University, Provo, UT 84602, USA. Electronic address: mktranstrum@byu.edu. 3. TA Instruments, 890 W 410 N St., Lindon, UT 84042, USA. Electronic address: cquinn@TAInstruments.com. 4. TA Instruments, 159 Lukens Drive, New Castle, DE 19720, USA. Electronic address: ndemarse@TAInstruments.com.
Abstract
BACKGROUND: Isothermal calorimetry allows monitoring of reaction rates via direct measurement of the rate of heat produced by the reaction. Calorimetry is one of very few techniques that can be used to measure rates without taking a derivative of the primary data. Because heat is a universal indicator of chemical reactions, calorimetry can be used to measure kinetics in opaque solutions, suspensions, and multiple phase systems and does not require chemical labeling. The only significant limitation of calorimetry for kinetic measurements is that the time constant of the reaction must be greater than the time constant of the calorimeter which can range from a few seconds to a few minutes. Calorimetry has the unique ability to provide both kinetic and thermodynamic data. SCOPE OF REVIEW: This article describes the calorimetric methodology for determining reaction kinetics and reviews examples from recent literature that demonstrate applications of titration calorimetry to determine kinetics of enzyme-catalyzed and ligand binding reactions. MAJOR CONCLUSIONS: A complete model for the temperature dependence of enzyme activity is presented. A previous method commonly used for blank corrections in determinations of equilibrium constants and enthalpy changes for binding reactions is shown to be subject to significant systematic error. GENERAL SIGNIFICANCE: Methods for determination of the kinetics of enzyme-catalyzed reactions and for simultaneous determination of thermodynamics and kinetics of ligand binding reactions are reviewed.
BACKGROUND: Isothermal calorimetry allows monitoring of reaction rates via direct measurement of the rate of heat produced by the reaction. Calorimetry is one of very few techniques that can be used to measure rates without taking a derivative of the primary data. Because heat is a universal indicator of chemical reactions, calorimetry can be used to measure kinetics in opaque solutions, suspensions, and multiple phase systems and does not require chemical labeling. The only significant limitation of calorimetry for kinetic measurements is that the time constant of the reaction must be greater than the time constant of the calorimeter which can range from a few seconds to a few minutes. Calorimetry has the unique ability to provide both kinetic and thermodynamic data. SCOPE OF REVIEW: This article describes the calorimetric methodology for determining reaction kinetics and reviews examples from recent literature that demonstrate applications of titration calorimetry to determine kinetics of enzyme-catalyzed and ligand binding reactions. MAJOR CONCLUSIONS: A complete model for the temperature dependence of enzyme activity is presented. A previous method commonly used for blank corrections in determinations of equilibrium constants and enthalpy changes for binding reactions is shown to be subject to significant systematic error. GENERAL SIGNIFICANCE: Methods for determination of the kinetics of enzyme-catalyzed reactions and for simultaneous determination of thermodynamics and kinetics of ligand binding reactions are reviewed.
Authors: Eva Illes-Toth; Christopher J Stubbs; Emma K Sisley; Jeddidiah Bellamy-Carter; Anna L Simmonds; Todd H Mize; Iain B Styles; Richard J A Goodwin; Helen J Cooper Journal: J Am Soc Mass Spectrom Date: 2022-06-08 Impact factor: 3.262