Evaluation of PDTC for removing Ni(II) from human serum transferrin in vitro

Pyrrolidine dithiocarbamate (PDTC)can be an oral chelator with pKa=3.300+/-0.002. It behaves as a bidentate ligand at serum pH. The effect of pH on Ni2+-Tf indicated that the maximum adsorption was at pH=7.4. The effective Ni-PDTC binding constant was determined (logk=11.1+/-0.1) for the 1:2 Ni(PDTC)2 complex using UV-vis spectra. The isosbestic point at 298 indicated that the complexation reaction was done directly (without side reaction). Removal of Ni from transferrin (Tf) was investigated by reverse titration of PDTC at 25 masculineC and pH=7.4 using UV-vis spectra. PDTC is able to remove 25% of Ni from human serum transferrin.