Various metal ions were capable of aggregating and precipitating conglutin gamma, an oligomeric glycoprotein purified from Lupinus albus seeds, at neutral pH values. The most effective metal ions, at 60-fold molar excess to the protein, were Zn2+, Hg2+ and Cu2+; a lower influence on the physical status of conglutin gamma was observed with Cr3+, Fe3+, Co2+, Ni2+, Cd2+, Sn2+ and Pb2+, while Mg2+, Ca2+ and Mn2+ had no effect at all. The insolubilisation of the protein with Zn2+, which is fully reversible, strictly depended on both metal concentration and pH, with middle points of the sharp transitions at three-fold molar excess and pH 6.5, respectively. Conglutin gamma is also fully retained on a metal affinity chromatography column at which Zn2+ and Ni2+ were complexed. A drop of pH below 6.0 and the use of chelating agents, such as EDTA and imidazole, fully desorbed the protein. A slightly lower binding to immobilised Cu2+ and Co2+ and no binding with Mg2+, Cd2+ and Mn2+ were observed. The role of the numerous histidine residues of conglutin gamma in the binding of Zn2+ is discussed.
Interaction of metal ions with lupin seed conglutin gamma / M. Duranti, A. Scarafoni, A. Di Cataldo, F. Sessa. - In: PHYTOCHEMISTRY. - ISSN 0031-9422. - 56:6(2001), pp. 529-533.
|Titolo:||Interaction of metal ions with lupin seed conglutin gamma|
|Parole Chiave:||Lupinus albus; leguminosae; white lupin; interactions; metals; zinc; conglutin gamma|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
|Data di pubblicazione:||2001|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/S0031-9422(00)00426-X|
|Appare nelle tipologie:||01 - Articolo su periodico|