title: Comparison of the Sulfonamide Inhibition Profiles of the β- and γ-Carbonic Anhydrases from the Pathogenic Bacterium Burkholderia pseudomallei.
abstract: We have cloned, purified, and characterized a β-carbonic anhydrase (CA, EC 4.2.1.1), BpsCAβ, from the pathogenic bacteriumBurkholderia pseudomallei, responsible for the tropical disease melioidosis. The enzyme showed high catalytic activity for the physiologic CO₂ hydration reaction to bicarbonate and protons, with the following kinetic parameters: kcatof 1.6 × 10⁵ s-1and kcat/KMof 3.4 × 10⁷ M-1s-1. An inhibition study with a panel of 38 sulfonamides and one sulfamate-including 15 compounds that are used clinically-revealed an interesting structure-activity relationship for the interaction of this enzyme with these inhibitors. Many simple sulfonamides and clinically used agents such as topiramate, sulpiride, celecoxib, valdecoxib, and sulthiame were ineffective BpsCAβ inhibitors (KI> 50 µM). Other drugs, such as ethoxzolamide, dorzolamide, brinzolamide, zonisamide, indisulam, and hydrochlorothiazide were moderately potent micromolar inhibitors. The best inhibition was observed with benzene-1,3-disulfonamides-benzolamide and its analogs acetazolamide and methazolamide-which showed KIin the range of 185-745 nM. The inhibition profile of BpsCAβ is very different from that of the γ-class enzyme from the same pathogen, BpsCAγ. Thus, identifying compounds that would effectively interact with both enzymes is relatively challenging. However, benzolamide was one of the best inhibitors of both of these CAs with KIof 653 and 185 nM, respectively, making it an interesting lead compound for the design of more effective agents, which may be useful tools for understanding the pathogenicity of this bacterium.
authors.affiliation: Laboratorio di Chimica Bioinorganica, Dipartimento Di Chimica, Università degli Studi di Firenze, Polo Scientifico, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. daniela.vullo@unifi.it.
authors.forename: Daniela
authors.initials: D
authors.lastname: Vullo
authors.affiliation: Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, 80131 Napoli, Italy. sonia.delprete@unifi.it.|Sezione di Scienze Farmaceutiche e Nutraceutiche, Dipartimento Neurofarba, Università degli Studi di Firenze, Via U. Schiff 6, 50019 Sesto Fiorentino, Florence, Italy. sonia.delprete@unifi.it.
authors.forename: Sonia
authors.initials: S
authors.lastname: Del Prete
authors.affiliation: Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, 80131 Napoli, Italy. pidifo@gmail.com.
authors.forename: Pietro
authors.initials: P
authors.lastname: Di Fonzo
authors.affiliation: Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, 80131 Napoli, Italy. vincenzo.carginale@cnr.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Carginale
authors.affiliation: School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia. w.donald@unsw.edu.au.
authors.forename: W Alexander
authors.initials: WA
authors.lastname: Donald
authors.affiliation: Sezione di Scienze Farmaceutiche e Nutraceutiche, Dipartimento Neurofarba, Università degli Studi di Firenze, Via U. Schiff 6, 50019 Sesto Fiorentino, Florence, Italy. claudiu.supuran@unifi.it.|School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia. claudiu.supuran@unifi.it.
authors.forename: Claudiu T
authors.initials: CT
authors.lastname: Supuran
authors.affiliation: Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, 80131 Napoli, Italy. clemente.capasso@ibbr.cnr.it.
authors.forename: Clemente
authors.initials: C
authors.lastname: Capasso
mesh_terms: D016957:Burkholderia pseudomallei / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D007698:Kinesis; D015394:Molecular Structure; D011994:Recombinant Proteins; D000077145:Sulfanilamide; D013424:Sulfanilamides / Q000494:pharmacology*
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D011994:Recombinant Proteins; D013424:Sulfanilamides; D000077145:Sulfanilamide
keywords: Burkholderia pseudomallei; carbonic anhydrase; metalloenzymes; pathogens; sulfonamide; β-class