Methods for studying the binding of aluminum by serum protein.
We describe methods for studying the binding of Al by protein in serum: ultrafiltration, gel filtration, and immuno-affinity chromatography. For ultrafiltration we used an Amicon YM10 cellophane membrane with a nominal cutoff of 10 000 Da to separate ultrafiltrable and non-ultrafiltrable Al. For gel filtration we used Sephacryl S-300, and for immuno-affinity chromatography we used anti-transferrin coupled to CNBr-activated Sepharose to identify the Al-binding protein. For 30 normal subjects 54% of the total Al in serum was non-ultrafiltrable; for 30 patients with chronic renal failure being treated by hemodialysis 67% was non-ultrafiltrable. In both groups transferrin was identified as the major Al-binding protein in the serum. Results of gel-filtration studies should be interpreted with caution: some gel media adsorb "free" Al, which can be subsequently taken up by transferrin or desferrioxamine passing through the column. We find affinity chromatography to be a specific and reliable method, suitable for use in quantitative studies.
D000328:Adult; D000535:Aluminum / Q000097:blood*; D001798:Blood Proteins / Q000378:metabolism*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D005260:Female; D006801:Humans; D007120:Immunochemistry; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007676:Kidney Failure, Chronic / Q000097:blood; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry; D011485:Protein Binding; D006435:Renal Dialysis; D013054:Spectrophotometry, Atomic; D014168:Transferrin / Q000378:metabolism; D014462:Ultrafiltration
D001798:Blood Proteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D014168:Transferrin; D000535:Aluminum