MS~n Analysis of a Glycoprotein Derived from Rat Leptomeningeal Cells with Matrix-Assisted Laser Desorption/Ionization Quadrupole Ion Trap Time-of-Flight Mass Spectrometry

摘要

Glycosylation is a major post-translational modification. However, oligosaccharide sequence and glycosylation site are hard to be analyzed in a general proteomics approach such as a combination of gel shift assay and MALDI-TOF MS. The reason seems to come from the fact that glycopeptide ions generated by protease digestion of glycoprotein are uninformative for database-depended protein identification. A reported analytical method using MALDI-QIT-TOF MSn is considered to be applicable for those glycopeptide analyses (1,2). Recently it was reported that the analytical method for glycopeptide was practically applicable for small-scale glycoprotein separated by 2-D gel electrophoresis (3). Here we report that determinations of N-glycan sequence and glycosylation site in addition to protein identification were performed for in-gel tryptic digests of a glycoprotein prepared from rat leptomeningeal cells.