STUDY OF THE POLYMORPHISM OF METALLOTHIONEINS BY ION-SPRAY MASS-SPECTROMETRY

Ion-spray mass spectrometry (IS-MS) is shown to be an attractive techn ique to identify and to differentiate among the sub-isoforms of metall othioneins (MT). Different modes of application of IS-MS are-discussed using the example of MT-2 rabbit liver prepurified by size-exclusion and anion-exchange chromatography. Direct IS-MS mode, microbore HPLC w ith on-line IS-MS detection of fully cadmiated (Cd-7-MT isofoms), HPLC with post-column acidification and detection of the apo-MT isoforms b y IS-MS, and with post-column acidification and detection of the Cd io n by IS-MS are discussed.