The distribution of zinc in human erythrocytes.

Gel permeation chromatography was used to fractionate zinc-bound constituents in haemolysates of human blood samples. The zinc content of the fractions was determined by electrothermal atomic absorption spectrometry. The zinc-containing enzyme, carbonic anhydrase, was identified by isoelectric focusing. A fraction of more than 0.9 of the zinc eluted from the column was bound to the carbonic anhydrase fraction. The fraction of zinc associated with unbound carbonic anhydrase was 0.786 of the total, and the remainder was found in a carbonic anhydrase-CO-haemoglobin complex.