Abstract
The reactivity of two isometallothioneins (two isoforms of rat liver zinc- and cadmiumthioneins) was compared in vitro. Reactions characteristic of metal-thiol mercaptide bonds were selected as follows; oxidative formation of intramolecular disulfide bonds by 5, 5'-dithiobis (2-nitrobenzoic acid), intra- and inter-molecular oxidations by air and ligand substitution reaction with ethylenediaminetetraacetic acid (EDTA). The relative ratio of the two isometallothioneins and the reaction products were determined by high performance liquid chromatograph-atomic absorption spectrophotometry. Metallothionein-I was shown to be more reactive than metallothionein-II in all reactions tested in this study.
