Zn-binding protein profile of rat liver cytosol. Chromatographic and electrophoretic study

65Zn2+ was given to rats per os and intraperitoneally for in vivo labelling of Zn2+-metalloproteins of cytosol. At the chromatographic analysis of the cytosol, two 65Zn2+-containing protein peaks were found in per os, while an additional low molecular weight third peak appeared in the intraperitoneal dosing samples. The chromatographic fractions were further separated by a non-denaturing gradient polyacrylamide electrophoresis technique. At the electrophoretic analysis of the chromatographic fractions the recovery of 65Zn2+ was the highest in samples taken from a second chromatographic peak (88%), which indicates the presence of proteins with exceptionally strong Zn2+-binding character in the 30-40 000 molecular weight fraction of the cytosol.