Separation of protein-bound copper and zinc in human plasma by means of gel filtration-ion-exchange chromatography

Abstract

A procedure for the separation of protein-bound copper and zinc fractions and of potassium and magnesium in plasma, involving chromatography on columns of DEAE-Sepharose CL-6B, is described. Copper, magnesium and zinc were measured by atomic-absorption spectroscopy and potassium by flame photometry. Most plasma samples yielded one copper and two zinc fractions and these were identified by the use of protein “markers.” Most of the copper appeared to be bound to caeruloplasmin and a lesser amount to albumin, whereas zinc appeared to be bound mainly to globulins with a smaller, variable, amount bound to albumin. Magnesium and potassium appeared as single peaks eluting in approximately the same fractions, ahead of the albumin peak.