Study on the Microstructure of Protein in Soluble Complexes Containing Bovine Serum Albumin and Hg~(2+)

The toxicity mechanism of Hg2+ for organisms and the change of protein microstructure for the interaction between heavy metal ions and proteins were investigated by Fourier transform infrared(FT-IR) spectrometer and circular dichroism(CD) spectrometer.The change of secondary structure of bovine serum albumin(BSA) were analyzed by IR spectral curve-fitting,and the percentage of secondary structure of BSA,including α-helix,β-sheet,β-turn and random,were calculated.The results form IR spectra indicated that BSA could react with Hg2+ by providing multiple binding sites,such as —NH,—SH and —OH groups.The curve fitting of IR spectra also indicated that the content of α-helix decreases while that of β-sheet increases,which is consistent with the results obtained from CD spectra.Therefore,the interaction of Hg2+ and BSA could lead to the change of BSA secondary structure from α-helix to β-sheet and the lost of its bio-activity,finally producing pathological change in organism.