Effect of the coordinate micro-environment on the structure of Hg(II)-serum albumin

Detailed studies on the UV spectra of Hg( II )-HSA or Hg( II )-BSA complexes nearby isoionic point were carried out in this paper. Compared with the spectra at physiological pH,the band nearby 250 nm of Hg( II )-BSA generally disappeared or widened and weakened, but the band at 290 nm of Hg( II )-BSA and Hg( II )-HSA remained nearly unchanged. These results support that these binding sites of Hg( II )-serum albumin may be located at seven pairs of adjacent disulfide bridges and there might be the structure of HgS4 tetrahedral configuration. For the first time,this paper put forward the solid figure of HgS4 tetrahedral configuration,and further discussed the results using the discrepancy of the coordinate micro-environment.