INTERACTIONS OF RARE-EARTH LENS WITH BOVINE BLOOD CU(ZN)-SUPEROXIDE DISMUTASE

The interactions of lanthanium trichloride and terbium trichloride with bovine blood Cu (Zn)-superoxide dismutase [Cu(Zn)-SOD] in the aqueous solution of hexamethylenetetrarnine buffer (pH = 6.3) have been studied by using fluorescece, CD and ESR spectra. The results indicated that rare earth ions were coordinated to the carboxyl groups of acidic amino acid residues which were far from active center of the Cu(Zn)-SOD molecule and only lightly disturbed the secondary structure of the enzyme protien, and made the coordination structure of enzyme-bound CU2+ come from the rhombchedron to the axial shape at 77 K and the activity of Cu(Zn)-SOD enzyme was not nearly changed at room temperature.