Competitive binding of chromium, cobalt and nickel to serum proteins

The competitive binding of chromium, cobalt and nickel chloride salts to murine serum proteins was studied in vitro. Individual metal salt solutions and combinations were incubated with 1:20 dilution of murine serum proteins for 24 h. Then free metal was removed by dialysis. The protein bound metal ions were analysed by graphite furnace atomic absorption spectroscopy. This study determined the saturation binding of cobalt and nickel to serum proteins. Murine serum is mostly saturated when cobalt or nickel is added at the concentration of 2 mol of metal to 1 mol of albumin. Chromium and cobalt have similar protein binding affinity, chromium and cobalt bind to protein in proportion to the added concentration ratio. However, nickel shows significant competition for chromium and cobalt binding moieties. This study provides a reference for future research on the biological role and properties of corrosion products.