Chemical interactions of mercury species and some transition and noble metals towards metallothionein (Zn_7MT-2) evaluated using SEC/ICP-MS, RP-HPLC/ESI-MS and MALDI-TOF-MS+

摘要

The chemical affinities of three submetallomes ("Mn, Co, Ni, Cu, Cd"; "Pd, Pt, Au”; and "Hg, CH_3Hg, C_2H_5Hg-THI") towards metallothionein-2 (Zn_7MT-2) in a physiological solution environment were evaluated using SEC/ICP-MS together with RP-HPLC/ESI-IT-MS and MALDI-TOF-MS, and followed the order: "Zn~(2+) < Cu~(2+), Cd~(2+) > Ni~(2+) > Mn~(2+), Co~(2+)"; "Pd~(2+) > Au~(3+) > Pt~(2+)"; and "Hg~(2+) > CH_3Hg+ > C_2H_5Hg-THI". Besides these, the structural change and composition of the CH_3Hg-MT-2 complexes formed during the CH_3Hg~+ titration process were further investigated using CD spectroscopy, RP-HPLC/ESI-MS and MALDI-TOF-MS, indicating that linear and more hydrophobic (CH_3Hg)_xMT-2 (x = 12, 13, 14, 15, 16, 17, 18, 19 and 20) were formed. Thisinformation is important in understanding the interactions of the metals with Zn_7MT-2 and their corresponding biological functions and toxicities.