Fast atom bombardment mass spectrometry (FAB-MS): analysis of complex carbohydrate chains of tissue kallikreins

Molecular ions and fragment ions of underivatized and permethylated oligosaccharides derived from human urinary kallikrein and some model glycoproteins gave information about the sugar composition and arrangement of sugars. These ions were conveniently created by FAB-MS in a JEOL JMS-HX110 high field high resolution mass spectrometer. Glycoprotein samples were digested with N-glycanase and the asparagine(Asn)-linked oligosaccharides were separated from polypeptides by Sephadex G-50 chromatography. The mixture of oligosaccharides was converted to the reduced p-aminobenzoic ethyl ester (ABEE) derivative and the components separated by HPLC on an ion-exchange (AX-10) column. Individual components were analyzed by negative FAB-MS using glycerol as a matrix. Permethylated oligosaccharides were also analyzed by positive FAB-MS.