Chelated mercury as a ligand in immobilized metal ion affinity chromatography of proteins

Chelation of mercuric ions by an iminodiacetate–Sepharose gel was evaluated. The retentive properties of iminodiacetate–Sepharose gel column was studied towards proteins varying the composition of eluting systems from 2-mercaptoethanol to NaCl and imidazole, determining also the extent of mercury leaching. It was demonstrated that chelated mercury contained free sites for interaction with proteins such as bromelain and recombinant human granulocyte colony stimulating factor from E. coli. The extraction of the latter by chromatography of its inclusion bodies solution on Hg(II)-loaded Sepharose–iminodiacetate gel was also evaluated.