Interaction of cupric ion with parvalbumin.
Cod parvalbumin, a calcium-binding protein, possesses a specific Zn2+ (or Cu2+) binding site per molecule. This work employed fluorescence energy transfer techniques to measure the distance between the Zn2+ (Cu2+) site and the stronger Ca(2+)-binding site in parvalbumin. Specifically, the distance between Tb3+ bound at the Ca2+ site and Co2+ bound to the Zn2+ (Cu2+) binding site was 10.3 +/- 0.9 A. Lastly, the effects of Cu2+ on the physico-chemical properties of parvalbumin were studied by measuring the accessibility of protein thiol groups to 5,5'-dithio bis(2-nitrobenzoic acid) and by its affinity for the fluorescent probe 4,4'-bis[1-(phenylamino)-8-naphthalene sulfonic acid] dipotassium salt. The thiol group accessibility decreased and the affinity to the fluorescent probe increased upon complexation of Cu2+ to the protein. It appears that the binding of Cu2+ converts parvalbumin to an apo-like state.
Permyakov
E A
EA
Institute of Biological Physics, Russian Academy of Sciences, Pushchino, Moscow region.
Kalinichenko
L P
LP
Derezhkov
V Y
VY
Antalik
M
M
Meinholtz
D C
DC
Berliner
L J
LJ
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent; D003300:Copper / Q000378:metabolism*; D005399:Fishes; D007700:Kinetics; D010320:Parvalbumins / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
D002413:Cations, Divalent; D010320:Parvalbumins; D003300:Copper; D002118:Calcium