Chromatographic separation of serum proteins and estimation of their zinc and copper content.

Abstract

Human serum proteins of blood donors and dialysis patients were separated by means of gel filtration chromatography. The resulting fractions were analyzed for copper and zinc. Separation resulted in 3 zinc peaks with a molecular weight of about 700,000, 300,000, and 75,000 Dalton, with alpha 2-macroglobulin co-eluting in the first and albumin co-eluting in the third zinc peak. The zinc protein(s) of the second peak remained unidentified. The three peaks contained, in succession, 0.72 +/- 0.30 mumol/L (4.8 +/- 1.6%), 1.26 +/- 0.37 mumol/L (8.5 +/- 1.7/1000) and 12.8 +/- 2.1 mumol/L (86.8 +/- 2.8%) of total zinc in the case of blood donors, and 1.19 +/- 1.05 mumol/L (9.2 +/- 7.2%), 0.97 +/- 0.22 mumol/L (8.0 +/- 2.6%), and 10.4 +/- 1.66 mumol/L (82.7 +/- 6.7%) in the case of dialysis patients. Separation followed by copper analysis resulted in the three peaks, as well, with a molecular weight of about 750,000, 140,000, and 75,000 dalton. The copper protein of the first peak remained unidentified, while coeruloplasmin co-eluted in the second and albumin in the third peak. The three peaks contained, in succession, 0.4 +/- 0.16 mumol/L (2.3 +/- 0.95%), 14.6 +/- 0.7 mumol/L (83.9 +/- 4.1%), and 2.4 +/- 0.6 mumol/L (13.7 +/- 3.5%) of total copper in the case of blood donors, and 0.5 +/- 0.73 mumol/L (2.2 +/- 3.2%), 19.5 +/- 1.1 mumol/L (90.5 +/- 4.9%), and 1.6 +/- 0.66 mumol/L (7.3 +/- 3.0/1000) in the case of dialysis patients. Limitation of the method is shown regarding separation of major from minor proteins and albumin from transferrin.