title: Chemometric analysis of voltammetric data on metal ion binding by selenocystine.
abstract: The behavior of selenocystine (SeCyst) alone or in the presence of various metal ions (Bi(3+), Cd(2+), Co(2+), Cu(2+), Cr(3+), Ni(2+), Pb(2+), and Zn(2+)) was studied using differential pulse voltammetry (DPV) over a wide pH range. Voltammetric data matrices were analyzed using chemometric tools recently developed for nonlinear data: pHfit and Gaussian Peak Adjustment (GPA). Under the experimental conditions tested, no evidence was found for the formation of metal complexes with Bi(3+), Cu(2+), Cr(3+), and Pb(2+). In contrast, SeCyst formed electroinactive complexes with Co(2+) and Ni(2+) and kinetically inert but electroactive complexes with Cd(2+) and Zn(2+). Titrations with Cd(2+), Co(2+), Ni(2+), and Zn(2+) produced data that were reasonably consistent with the formation of stable 1:1 M(SeCyst) complexes.
authors.affiliation: Departament de Química Analítica, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, E-08028-Barcelona, Spain.
authors.forename: Rui
authors.initials: R
authors.lastname: Gusmão
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Díaz-Cruz
authors.forename: Cristina
authors.initials: C
authors.lastname: Ariño
authors.forename: Miquel
authors.initials: M
authors.lastname: Esteban
mesh_terms: D001665:Binding Sites; D003553:Cystine / Q000031:analogs & derivatives* / Q000737:chemistry; D055664:Electrochemical Techniques; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D016566:Organoselenium Compounds / Q000737:chemistry*
chemical_list: D007477:Ions; D019216:Metals, Heavy; D016566:Organoselenium Compounds; C009226:selenocystine; D003553:Cystine