title: Extending ITC to Kinetics with kinITC.
abstract: Isothermal titration calorimetry (ITC) has long been used for kinetic studies in chemistry, but this remained confined to enzymatic studies in the biological field. In fact, the biological community has long had the tendency of ignoring the kinetic possibilities of ITC considering it solely as a thermodynamic technique, whereas surface plasmon resonance is seen as the kinetic technique par excellence. However, the primary signal recorded by ITC is a heat power which is directly related to the kinetics of the reaction. Here, it is shown how this kinetic signal can be recovered by using kinITC, the kinetic extension of ITC. The theoretical basis of kinITC is detailed for the most common situation of a second-order reaction A+B Ω C characterized by kinetic parameters kon, koff. A simplified kinITC-ETC method based upon the determination of an "Equilibration Time Curve" (ETC) is presented. The ETC is obtained by automatic determination of the "effective end" of each injection. The method is illustrated with experimental results with a comparison to Surface Plasmon Resonance (SPR) data. kon values were obtained in a wide range, from 10(3) to 0.5×10(6) M(-1) s(-1). All procedures were implemented in the program AFFINImeter (https://www.affinimeter.com/).
authors.affiliation: Biophysics & Structural Biology Team, IBMC, UPR9002-CNRS, University of Strasbourg, Strasbourg, France. Electronic address: p.dumas@ibmc-cnrs.unistra.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Dumas
authors.affiliation: Biophysics & Structural Biology Team, IBMC, UPR9002-CNRS, University of Strasbourg, Strasbourg, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Ennifar
authors.affiliation: Biophysics & Structural Biology Team, IBMC, UPR9002-CNRS, University of Strasbourg, Strasbourg, France.
authors.forename: Cyrielle
authors.initials: C
authors.lastname: Da Veiga
authors.affiliation: Biophysics & Structural Biology Team, IBMC, UPR9002-CNRS, University of Strasbourg, Strasbourg, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bec
authors.affiliation: University of Bordeaux, Laboratoire ARNA, Pessac, France; INSERM U869, Laboratoire ARNA, Pessac, France.
authors.forename: William
authors.initials: W
authors.lastname: Palau
authors.affiliation: University of Bordeaux, Laboratoire ARNA, Pessac, France; INSERM U869, Laboratoire ARNA, Pessac, France.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Di Primo
authors.affiliation: AFFINImeter Scientific & Development Team, Software 4 Science Developments, S. L. Ed. Emprendia, Campus Vida, Santiago de Compostela, A Coruña, Spain; Department of Applied Physics, Faculty of Physics, University of Santiago de Compostela, Campus Vida, Santiago de Compostela, A Coruña, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Piñeiro
authors.affiliation: AFFINImeter Scientific & Development Team, Software 4 Science Developments, S. L. Ed. Emprendia, Campus Vida, Santiago de Compostela, A Coruña, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Sabin
authors.affiliation: AFFINImeter Scientific & Development Team, Software 4 Science Developments, S. L. Ed. Emprendia, Campus Vida, Santiago de Compostela, A Coruña, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Muñoz
authors.affiliation: AFFINImeter Scientific & Development Team, Software 4 Science Developments, S. L. Ed. Emprendia, Campus Vida, Santiago de Compostela, A Coruña, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Rial
mesh_terms: D002151:Calorimetry / Q000379:methods*; D007700:Kinetics
keywords: Biological calorimetry; Equilibration time curve; ITC; Kinetics; Microcalorimetry; kinITC