DEVELOPMENT OF A CAPILLARY ELECTROPHORESIS METHOD FOR THE CHARACTERIZATION OF ENZYMATIC PRODUCTS ARISING FROM THE CARBAMOYLASE DIGESTION OFPARALYTIC SHELLFISH POISONING TOXINS

A sample stacking procedure is presented for the capillary electrophor etic (CE) separation of paralytic shellfish poisoning (PSP) toxins dis solved in high ionic strength buffers. The application of such a stack ing procedure prior to the zone electrophoretic separation is demonstr ated for the analysis of decarbamoyl toxins arising from the digestion of PSP toxins by an hydrolytic enzyme from little neck clams (Prototh aca staminea). Improvements in separation efficiency facilitated ident ification and quantitation of substrates and enzymatic products presen t in the digest using CE. The separation conditions developed were fou nd to be entirely compatible with electrospray mass spectrometry, whic h permitted the analysis of PSP toxins and their decarbamoyl derivativ es present in the low micromolar range in crude enzyme digests. The pr oducts released during the enzymatic digestion were identified using C E combined with tandem mass spectrometry.