title: Combined use of the potential shift correction and the simultaneous treatment of spectroscopic and electrochemical data by multivariate curve resolution: analysis of a Pb(II)-phytochelatin system.
abstract: The combined use of differential pulse polarography (DPP), circular dichroism (CD) and multivariate curve resolution by alternating least squares (MCR-ALS), with potential shift correction for data analysis, provides valuable information on the complexation of Pb(ii) by the phytochelatin (gamma-Glu-Cys)(3)-Gly (PC(3)). All data confirm the formation of the predominant 1 : 1 Pb-PC(3) complex. However, in the presence of an excess of Pb(ii), the same complex seems to be present but with some modification in its structure. This is suggested by the shift towards more negative potentials of the DPP signal, and by a dramatic change in CD spectra. This evolution seems to be more related to a conformational change of the complex than with a modification of the electrochemical process kinetics.
authors: Departament de Química Analítica. Facultat de Química. Universitat de Barcelona, Martí i Franquès 1-11, E-08028, Barcelona, Spain.
authors: Arístides
authors: A
authors: Alberich
authors: José Manuel
authors: JM
authors: Díaz-Cruz
authors: Cristina
authors: C
authors: Ariño
authors: Miquel
authors: M
authors: Esteban
mesh_terms: D000818:Animals; D002942:Circular Dichroism; D007854:Lead / Q000737:chemistry*; D016018:Least-Squares Analysis; D008956:Models, Chemical; D054811:Phytochelatins / Q000737:chemistry*; D011048:Polarography
chemical_list: D007854:Lead; D054811:Phytochelatins