Gel filtration chromatography of metallothionein obtained from rabbit liver

Metallothioneins (MTs) are known as heat-stable proteins and are able to be precipitated at 100 degrees C for 2 min. The aim of this work was to determine the content of metallothioneins and zinc in fraction after gel filtration (Sephadex G-75). The research was supposed to answer the question whether metallothioneins contain zinc ions after heat-treated cytosol. The rabbit liver cytosol was initially heat-treated to remove the heat-liable proteins and then cytosol was applied to a gel filtration column (Sephadex G-75). Metallothioneins content in each eluted fraction was measured by cadmium-hemoglobin affinity assay using the cadmium isotope (109Cd). Another experiment was conducted to further confirm whether the MTs peak contains zinc. A metal peak appeared at low molecular weight fractions. The metallothioneins isolated from rabbit liver contain zinc.