Binding of aluminum to human serum transferrin, human serum albumin and rat serum proteins.

Abstract

Human serum transferrin (HSTF), human serum albumin (HSA) and rat serum were compared for their interaction with AlCl3, in a Tris-HCl buffer solutions (pH 7.4). The AlCl3 was tested in series of concentrations in the range of 50 microM up to 500 microM. HSTF, HSA and their 1:1 mixture and rat serum were incubated at 37 degrees C with series of AlCl3 concentrations. The protein profile of the incubated solutions were compared to control using SDS-PAGE and FPLC tests. The results indicated that HSTF was more specifically responsive to AlCl3 showing a characteristic increase in its UV absorption, peak and area dimensions. Simultaneously, HSA was less affected, but it showed a significant shift with an increase in molecular weight accompanied with a change in its profile. The respective bands of transferrin and albumin in rat serum behaved similarly. The SDS-PAGE and FPLC data coincided and confirmed the preferential affinity of HSTF to bind with Al3+. These results support the suggestion of using HSTF for monitoring levels of Al3+ in human blood samples of exposed population. The importance of further developing such a biomarker is the increased demand for early detection of the hazardous levels of Al3+ in relation to its long term neurotoxic adverse effects.