title: Enzyme-catalyzed and binding reaction kinetics determined by titration calorimetry.
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.
  
  
  METHODS
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.affiliation: Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA. Electronic address: lee_hansen@byu.edu.
authors.forename: Lee D
authors.initials: LD
authors.lastname: Hansen
authors.affiliation: Department of Physics & Astronomy, Brigham Young University, Provo, UT 84602, USA. Electronic address: mktranstrum@byu.edu.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Transtrum
authors.affiliation: TA Instruments, 890 W 410 N St., Lindon, UT 84042, USA. Electronic address: cquinn@TAInstruments.com.
authors.forename: Colette
authors.initials: C
authors.lastname: Quinn
authors.affiliation: TA Instruments, 159 Lukens Drive, New Castle, DE 19720, USA. Electronic address: ndemarse@TAInstruments.com.
authors.forename: Neil
authors.initials: N
authors.lastname: Demarse
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D055162:Biocatalysis; D002151:Calorimetry / Q000379:methods; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology; D006358:Hot Temperature; D006801:Humans; D006836:Hydro-Lyases / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D009097:Multienzyme Complexes / Q000737:chemistry*; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry*; D013395:Sucrose / Q000737:chemistry; D013816:Thermodynamics; D016963:Thermus thermophilus / Q000737:chemistry / Q000201:enzymology; D014357:Trypsin / Q000737:chemistry*; D043324:beta-Fructofuranosidase / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D013395:Sucrose; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D043324:beta-Fructofuranosidase; D014357:Trypsin; D006836:Hydro-Lyases; C021455:3-isopropylmalate dehydratase
keywords: Calorimetry; Enzyme; ITC; Ligand binding