[Interaction of copper nd zinc cations with calcium-binding proteins].
Interactions of the calcium binding proteins, parvalbumin from cod muscles, alpha-lactalbumin from cow milk and calmodulin from bovine brain, with Cu2+ and Zn2+ ions have been studied by intrinsic fluorescence and microcalorimetry methods. It was revealed that parvalbumin binds one Cu2+ ion per molecule with association constant from 10(5) to 10(6) M-1. Zn2+ ions seem to compete for the same site which does not coincide with the two Ca2+ and Mg2+ binding sites. alpha-Lactalbumin contains from 2 to 4 Cu2+ and Zn2+ binding sites, the number and affinities of which depend on Ca2+ concentration. Calmodulin has similar Cu2+ and Zn2+ binding sites. The binding of Cu2+ and Zn2+ ions to parvalbumin and alpha-lactalbumin changes the shape and position of their thermal denaturation transitions. The results obtained together with the literature data show that the ability to interact with Cu2+ and Zn2+ ions is a property inherent to many calcium-binding proteins, which may play a physiological role for some of them.
Permiakov
E A
EA
Kalinichenko
L A
LA
Morozova
L A
LA
Derezhkov
Iu V
IuV
Bagelova
J
J
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D002412:Cations; D002417:Cattle; D003300:Copper / Q000378:metabolism*; D005399:Fishes; D007700:Kinetics; D007768:Lactalbumin / Q000378:metabolism; D010320:Parvalbumins / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D015032:Zinc / Q000378:metabolism*
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D002412:Cations; D010320:Parvalbumins; D003300:Copper; D007768:Lactalbumin; D015032:Zinc
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