Mass spectrometry of L-beta-aspartamido carbohydrates isolated from ovalbumin

Using ovalbumin as a starting material, we have isolated and purified relatively large stocks of known glycopeptides for use as models with which to investigate and develop mass spectrometric procedures for the analysis of this class of compounds. In the process, we have discovered six new components in the L-beta-aspartamido carbohydrate fraction of ovalbumin. Positive and negative fast atom bombardment mass spectra, produced on a KRATOS MS50-TC, confirm that the newly found chromatographic peaks correspond to as yet unidentified compounds in the molecular weight range of 1000-3000. Fragment ion peaks present in the mass spectra of some of the unknown compounds can be rationalized in terms of the fragment ion patterns established from the structures of the known glycoasparagines.