title: Ion mobility spectrometry focusing on speciation analysis of metals/metalloids bound to carbonic anhydrase.
abstract: In the present work, traveling wave ion mobility spectrometry-mass spectrometry (TWIMS-MS) was applied to speciation analysis of metalloproteins. The influence of pH on complexation conditions between some metals and bovine carbonic anhydrase was evaluated from pH 6 to 9, as well as the time involved in their complexation (0-24 h). Employing TWIMS-MS, two conformational states of bovine carbonic anhydrase were observed with charge states of +12 and +11; these configurations being evaluated in terms of the folded state of the apo form and this protein (at charge state +11) being linked to barium, lead, copper, and zinc in their divalent forms. Metalloprotein speciation analysis was carried out for copper (Cu(+) and Cu(2+)), lead (Pb(2+) and Pb(4+)), and selenium (Se(4+) and Se(6+)) species complexed with bovine carbonic anhydrase. Mobilities of all complexed species were compared, also considering the apo form of this protein.
authors.affiliation: Spectrometry, Sample Preparation and Mechanization Group, GEPAM, Institute of Chemistry, University of Campinas-UNICAMP, P.O. Box 6154, Campinas, SP, 13083-970, Brazil.
authors.forename: Gustavo de Souza
authors.initials: Gde S
authors.lastname: Pessôa
authors.forename: Eduardo Jorge
authors.initials: EJ
authors.lastname: Pilau
authors.forename: Fábio Cesar
authors.initials: FC
authors.lastname: Gozzo
authors.forename: Marco Aurélio Zezzi
authors.initials: MA
authors.lastname: Arruda
mesh_terms: D002256:Carbonic Anhydrases / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D058955:Metalloids / Q000737:chemistry* / Q000378:metabolism; D008670:Metals / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D058955:Metalloids; D008670:Metals; D002256:Carbonic Anhydrases