title: Carbonic anhydrase VII is S-glutathionylated without loss of catalytic activity and affinity for sulfonamide inhibitors.
abstract: Human carbonic anhydrase (CA, EC 4.2.1.1) VII is a cytosolic enzyme with high carbon dioxide hydration activity. Here we report an unexpected S-glutathionylation of hCA VII which has also been observed earlier in vivo for hCA III, another cytosolic isoform. Cys183 and Cys217 were found to be the residues involved in reaction with glutathione for hCA VII. The two reactive cysteines were then mutated and the corresponding variant (C183S/C217S) expressed. The native enzyme, the variant and the S-glutathionylated adduct (sgCA VII) as well as hCA III were fully characterized for their CO(2) hydration, esterase/phosphatase activities, and inhibition with sulfonamides. Our findings suggest that hCA VII could use the in vivo S-glutathionylation to function as an oxygen radical scavenger for protecting cells from oxidative damage, as the activity and affinity for inhibitors of the modified enzyme are similar to those of the wild type.
authors.affiliation: Istituto di Biostrutture e Bioimmagini-CNR, Napoli, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Truppo
authors.forename: Claudiu T
authors.initials: CT
authors.lastname: Supuran
authors.forename: Annamaria
authors.initials: A
authors.lastname: Sandomenico
authors.forename: Daniela
authors.initials: D
authors.lastname: Vullo
authors.forename: Alessio
authors.initials: A
authors.lastname: Innocenti
authors.forename: Anna
authors.initials: A
authors.lastname: Di Fiore
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Alterio
authors.forename: Giuseppina
authors.initials: G
authors.lastname: De Simone
authors.forename: Simona M
authors.initials: SM
authors.lastname: Monti
mesh_terms: D000595:Amino Acid Sequence; D002257:Carbonic Anhydrase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D002256:Carbonic Anhydrases / Q000235:genetics / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics; D026422:S-Nitrosoglutathione / Q000737:chemistry; D016415:Sequence Alignment; D021241:Spectrometry, Mass, Electrospray Ionization; D013449:Sulfonamides / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D020033:Protein Isoforms; D013449:Sulfonamides; D026422:S-Nitrosoglutathione; D002256:Carbonic Anhydrases; C477051:carbonic anhydrase VI