CAPILLARY ELECTROPHORESIS-BASED SEPARATION OF TRANSFERRIN SIALOFORMS IN PATIENTS WITH CARBOHYDRATE-DEFICIENT GLYCOPROTEIN SYNDROME

The heterogeneity associated with protein glycoforms has been a challe nge to analytical chemists and the subject of structure-function studi es for biochemists since their presence in biological systems had been confirmed some three decades ago. Initial investigations led to disco veries of synthetic and degradative pathways, and brief forays into fu nctional determination of the ''glyco'' portion on the protein activit y in glycoproteins. Only recently has it come to our understanding tha t variations from the ''normal'' glycosylation patterns might be indic ative of pathological states. The presence of certain transferrin (Tf) glycoforms in human serum has been shown to correlate with certain cl inical syndromes. Hence, the ability to separate and quantitatively me asure the various forms of human Tf has become increasingly important. It this study, we demonstrate that a simple method utilizing a DB-17- coated capillary to slow endoosmotic flow and a sieving buffer contain ing hydroxyethyl cellulose allows for the resolution of sialoforms of transferrin. An analysis time of less than eight minutes allows for ba seline resolution of the lower sialoforms of Tf, presenting a simple, rapid test for carbohydrate-deficient transferrin (CDT). We demonstrat e the utility of this methodology for the facile diagnosis of carbohyd rate-deficient glycoprotein syndrome, and postulate that it may allow for the detection of other carbohydrate-deficient protein-related dise ase states.