Interaction of selected divalent metal ions with human ataxin-3 Q36

doi:10.1007/s00775-009-0561-1

Interaction of selected divalent metal ions with ...

Bibliographic description

title:	Interaction of selected divalent metal ions with human ataxin-3 Q36
author:	Stawoska Iwona, Wesełucha-Birczyńska Aleksandra , Regonesi Maria Elena, Riva Matteo, Tortora Paolo, Stochel Grażyna
Journal title:	JBIC. Journal of Biological Inorganic Chemistry
volume:	14
issue:	8
date of publication:	2009
pages:	1175-1185
ISSN:	0949-8257
eISSN:	1432-1327
DOI:	10.1007/s00775-009-0561-1
language:	English
Journal language:	English
abstract in english:	The mode of interaction of ataxin-3 Q36 (AT-3 Q36) with selected endogenous and exogenous metal ions, namely, Zn^{2+}, Cu^{2+}, Ni^{2+}, and Cd^{2+}, was examined. Metal-ion-induced structural changes of the protein were monitored by fluorescence as well as Fourier transform Raman spectroscopy. We found that the cations tested lead to a decrease in α-helical content and a concurrent increase in β-sheet as well as undefined (β-turn and random-coil) structures. The most evident effect was observed for copper and nickel cations. After titration with these cations, the AT3 Q36 secondary structure content (27% α-helices in the presence of either ion, 31 and 27% β-sheets for Cu^{2+} and Ni^{2+}, respectively) was similar to that observed for the aggregated form of the protein (27% α-helices, 36% β-sheets). Using the 1-anilinonaphthalene-8-sulfonate hydrophobic fluorescence probe, we showed that the presence of the metal ions tested led to the formation of solvent-exposed hydrophobic patches of AT-3 Q36, and that such an effect decreased with increasing ionic radius.
keywords in english:	ataxin-3, Fourier transform Raman, metal ions, secondary structures
affiliation:	Wydział Chemii : Zakład Chemii Nieorganicznej, Wydział Chemii : Zakład Fizyki Chemicznej
type:	journal article
subtype:	academic paper