Isolation, characterization, and evaluation of metallothionein in renal transplant patients

The plasma metallothionein concentration was studied in renal transplant patients. These patients are submitted to an attack of free radicals catalyzed by metals such as copper, zinc, cadmium, and others. The function of metallothionein is to bind toxic metals inhibiting the attack of free radicals and oxidative stress that patients receiving renal transplants are submitted to. This is the reason for studying this protein in this work. The metalloprotein was separated from the plasma by thermoprecipitation and molecular exclusion chromatography with Sephadex G-75 followed by anionic-ionic exchange chromatographic purification with a CINa gradient. Identification was done by SDS electrophoresis in acrylamide gel with markers and commercial protein. Finally, determinations were made by atomic absorption, silver saturation method. In this work, determinations were made in the plasma of 11 patients before and 48 h and 1 and 2 weeks after renal transplantation. The same study was carried out in parallel in a control group of 11 blood donors. The results obtained show the existence in the plasma of metallothionein, with lower concentrations in patients than in controls (19 +/- 1.2 mg vs. 12 +/- 1.2 mg). The levels were lowest in the patient group analyzed 48 h after having received the transplant (6.34 mg) and had recovered slightly one and two weeks later.