Metal-specific structural changes in parvalbumin.
Parvalbumin is a small protein of EF-hand family whose main role is considered to be metal buffering. Recent evidences indicate that parvalbumin also fulfills more complicated functions, which may be determined by the diversity in structural changes in response to the binding of different metal cations. In the present work the conformations of α and β isoforms of pike parvalbumin in the Ca(2+)- and Mg(2+)-loaded state were studied by intrinsic fluorescence, circular dichroism and bis-ANS extrinsic fluorescence. We have determined the structural region causing different spectral response on the binding of Mg(2+)- and Ca(2+) ions in pike β-parvalbumin. Our data reveal similarity of the metal-bound forms of α-parvalbumin. In contrast, those of β isoform differ significantly in the tyrosine spectral range. We also discuss the possible physiological consequences of the structural rearrangements accompanied Mg(2+)/Ca(2+) exchange in pike β-parvalbumin.
Institute for Biological Instrumentation of the Russian Academy of Sciences, Institutskaya Str. 7, Pushchino, Moscow Region 142290, Russia. bakunts.a@gmail.com
Anush G
AG
Bakunts
D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D002118:Calcium / Q000737:chemistry*; D002942:Circular Dichroism; D005453:Fluorescence; D008274:Magnesium / Q000737:chemistry*; D010320:Parvalbumins / Q000737:chemistry*; D020033:Protein Isoforms / Q000737:chemistry; D014466:Ultraviolet Rays
D000817:Anilino Naphthalenesulfonates; D010320:Parvalbumins; D020033:Protein Isoforms; C035763:5,5'-bis(8-(phenylamino)-1-naphthalenesulfonate); D008274:Magnesium; D002118:Calcium