MONITORING METAL-ION FLUX IN REACTIONS OF METALLOTHIONEIN AND DRUG-MODIFIED METALLOTHIONEIN BY ELECTROSPRAY MASS-SPECTROMETRY

The capabilities of electrospray ionization mass spectrometry are demo nstrated for monitoring the flux of metal ions out of and into the met alloprotein rabbit liver metallothionein and, in one example, chloramb ucil-alkylated metallothionein. Metal ion transfers may be followed as the reactions proceed in situ to provide kinetic information. More un iquely to this technique, metal ion stoichiometries may be determined for reaction intermediates and products. Partners used in these studie s include EDTA, carbonic anhydrase, a zinc-bound hexamer of insulin, a nd the core domain of bacteriophage T4 gene 32 protein, a binding prot ein for single-stranded DNA.