BINDING OF ALUMINUM TO HUMAN SERUM TRANSFERRIN, HUMAN SERUM-ALBUMIN AND RAT SERUM-PROTEINS

Human serum transferrin (HSTF), human serum albumin (HSA) and rat seru m 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 mu M up to 500 mu M. HSTF, HSA and their 1:1 mixtur e and rat serum were incubated at 37 degrees C with series of AlCl3 co ncentrations. The protein profile of the incubated solutions were comp ared to control using SDS-PAGE and FPLC tests. The results indicated t hat HSTF was more specifically responsive to AlCl3 showing a character istic increase in its UV absorption, peak and area dimensions. Simulta neously, HSA was less affected, but it showed a significant shift with an increase in molecular weight accompanied with a change in its prof ile. The respective bands of transferrin and albumin in rat serum beha ved 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 b lood samples of exposed population. The importance of further developi ng such a biomarker is the increased demand for early detection of the hazardous levels of Al3+ in relation to its long term neurotoxic adve rse effects.