title: Label-free characterization of carbonic anhydrase-novel inhibitor interactions using surface plasmon resonance, isothermal titration calorimetry and fluorescence-based thermal shift assays.
abstract: This work describes the development of biophysical unbiased methods to study the interactions between new designed compounds and carbonic anhydrase II (CAII) enzyme. These methods have to permit both a screening of a series of sulfonamide derivatives and the identification of a lead compound after a thorough study of the most promising molecules. Interactions data were collected using surface plasmon resonance (SPR) and thermal shift assay (TSA). In the first step, experiments were performed with bovine CAII isoform and were extended to human CAII. Isothermal titration calorimetry (ITC) experiments were also conducted to obtain thermodynamics parameters necessary for the processing of the TSA data. Results obtained with this reference methodology demonstrate the effectiveness of SPR and TSA. KD values obtained from SPR data were in perfect accordance with ITC. For TSA, despite the fact that the absolute values of KD were quite different, the same affinity scale was obtained for all compounds. The binding affinities of the analytes studied vary by more than 50 orders of magnitude; for example, the KD value determined by SPR were 6 ± 4 and 299 ± 25 nM for compounds 1 and 3, respectively. This paper discusses some of the theoretical and experimental aspects of the affinity-based methods and evaluates the protein consumption to develop methods for the screening of further new compounds. The double interest of SPR, that is, for screening and for the quick thorough study of the interactions parameters (ka , kd , and KD ), leads us to choose this methodology for the study of new potential inhibitors.
authors.affiliation: Université Lille Nord de France, F-59000, Lille, France; UDSL, EA-4481, UFR Pharmacie, Université Lille Nord de France, F-59000, Lille, France.
authors.forename: Tiphaine
authors.initials: T
authors.lastname: Rogez-Florent
authors.forename: Laetitia
authors.initials: L
authors.lastname: Duhamel
authors.forename: Laurence
authors.initials: L
authors.lastname: Goossens
authors.forename: Perrine
authors.initials: P
authors.lastname: Six
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Drucbert
authors.forename: Patrick
authors.initials: P
authors.lastname: Depreux
authors.forename: Pierre-Marie
authors.initials: PM
authors.lastname: Danzé
authors.forename: David
authors.initials: D
authors.lastname: Landy
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Goossens
authors.forename: Catherine
authors.initials: C
authors.lastname: Foulon
mesh_terms: D000818:Animals; D002151:Calorimetry; D024402:Carbonic Anhydrase II / Q000378:metabolism*; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D002417:Cattle; D005453:Fluorescence; D006801:Humans; D007700:Kinetics; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D013816:Thermodynamics
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D024402:Carbonic Anhydrase II
keywords: binding; carbonic anhydrase; diarylpyrazole sulfonamide; fluorescence-based thermal shift assay; isothermal titration calorimetry; kinetics; surface plasmon resonance; thermodynamics