HIGH-PERFORMANCE LIQUID-C CHROMATOGRAPHY FOR STUDYING METALLOTHIONEINPOLYMORPHISM

Four commercially available metallothioneins from rabbit liver (RL, RL I, RL II) and from horse kidney (HK) have been studied by size exclus ion chromatography and by reverse phase chromatography, to characteriz e their polymorphism. The isoforms are detected by UV at 250 nm. Separ ations by size exclusion show that the metallothioneins are partially dimerized, with molar rates of dimer ranging from 5% for HK to 15% for RL II. The four chromatograms obtained by reverse phase exhibit a dif ferent morphology: RL separates in four main isoforms, RL I into two, RL II into three, and HK into two. An attribution of the various peaks for the RL, RL I, and RL II series is proposed. The comparable result s obtained by the two methods allow us to estimate that RL is composed of 20-30% RL I and 70-80% of RL II.