par Rubio Fernandez, Lucia ;Vandenbussche, Guy ;Roosens, Nancy ;Govaerts, Cédric ;Goormaghtigh, Erik ;Verbruggen, Nathalie
Référence Biochimica et biophysica acta, 1824, 9, page (1016-1023)
Publication Publié, 2012
Référence Biochimica et biophysica acta, 1824, 9, page (1016-1023)
Publication Publié, 2012
Article révisé par les pairs
Résumé : | Metallothioneins (MT) are low molecular weight proteins with cysteine-rich sequences that bind heavy metals with remarkably high affinities. Plant MTs differ from animal ones by a peculiar amino acid sequence organization consisting of two short Cys-rich terminal domains (containing from 4 to 8 Cys each) linked by a Cys free region of about 30 residues. In contrast with the current knowledge on the 3D structure of animal MTs, there is a striking lack of structural data on plant MTs. We have expressed and purified a type III MT from Noccaea caerulescens (previously Thlaspi caerulescens). This protein is able to bind a variety of cations including Cd2+, Cu2+, Zn 2+ and Pb2+, with different stoichiometries as shown by mass spectrometry. The protein displays a complete absence of periodic secondary structures as measured by far-UV circular dichroism, infrared spectroscopy and hydrogen/deuterium exchange kinetics. When attached onto a BIA-ATR biosensor, no significant structural change was observed upon removing the metal ions. © 2012 Elsevier B.V. |