Publication Type Journal Article
Title Binding of Oxovanadium(IV) Complexes to Blood Serum Albumins
Authors Enoch Cobbina Sameena Mehtab Isabel Correia Gisela Goncalves Ana Isabel Tomaz Isabel Cavaco Tamas Jakusch Eva Enyedi Tamas Kiss J.C. Pessoa
Groups BIOIN
Journal JOURNAL OF THE MEXICAN CHEMICAL SOCIETY
Year 2013
Month July
Volume 57
Number 3
Pages 180-191
Abstract In this work the binding of (VO2+)-O-IV and (VO)-O-IV-complexes to serum albumins \human serum albumin (HSA), bovine serum albumin (BSA) and porcine serum albumin (PSA)\ are studied using circular dichroism (CD), electron paramagnetic resonance (EPR) and visible absorption spectroscopy. The results confirm previous findings that (VO2+)-O-IV occupies at least two types of binding sites on albumin: the strong vanadium binding site (designated by VBS1) and the weak vanadium binding sites (designated by VBS2). VBS1 binds 1 mol equivalent of (VO2+)-O-IV. On the other hand VBS2 correspond to binding of several mol equivalents of (VO)-O-IV, and studies done with PSA in the presence of excess Zn-II ions indicate that VSB2 corresponds to two distinct types of sites. The hyperfine coupling constant A(z) for (VO2+)-O-IV binding at VBS2 on HSA and BSA are all very similar (similar to 168 x 10(-4) cm(-1)) but differ slightly on PSA (similar to 166 x 10(-4) cm(-1)) due to differences in the binding sets. When ((VO)-O-IV)-HSA systems are titrated with maltol ternary species of (maltol)(m)((VO)-O-IV)(m)HSA and (maltol)(2m)((VO)-O-IV)(m)HSA stoichiometry form which are clearly distinguishable from the binary ((VO)-O-IV)-HSA system by the type and intensity of the CD spectra recorded. Changes are also observable in the intensity of the X-band EPR spectra, but not much in the hyperfine coupling constants A(z), which are all in the range 166-167 x 10(-4) cm(-1). The results further demonstrate that the presence of maltol may enhance the binding of (VO)-O-IV to albumin.
DOI http://dx.doi.org/
ISBN
Publisher
Book Title
ISSN 1870-249X
EISSN 1665-9686
Conference Name
Bibtex ID ISI:000327408800005
Observations
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