Structural characterization of glycopeptides by N-terminal protein ladder sequencing.
High-sensitivity and high-throughput mass spectrometry (MS) has become an important tool for characterizing glycopeptides. Here, we analyzed synthetic O-linked glycopeptides using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS. First, we applied MALDI-quadrupole ion trap (QIT)-TOF MS, which enables collision-induced dissociation-MSn analysis for fine structural characterization. Subsequent MS/MS of sodium adduct ions selected as precursor ions yielded detailed information about the site of oligosaccharide attachment as well as the carbohydrate and amino acid sequences; however, these MS/MS spectra were very complex. To obtain easily interpretable and simple spectra, we used N-terminal protein ladder sequencing coupled with MALDI-TOF MS. From the extremely simple resulting spectra, we were able to determine the glycosylation sites, amino acid sequences, and oligosaccharide molecular weights of the glycopeptides.
Suzuki
Yusuke
Y
Sphingolipid Expression Laboratory, Supra Biomolecular System Research Group, RIKEN Frontier Research System, Wako-shi, Saitama 351-0198, Japan.
Suzuki
Minoru
M
Nakahara
Yoshiaki
Y
Ito
Yukishige
Y
Ito
Emi
E
Goto
Naoko
N
Miseki
Kozo
K
Iida
Junko
J
Suzuki
Akemi
A
D000595:Amino Acid Sequence; D001665:Binding Sites; D006020:Glycopeptides / Q000032:analysis* / Q000737:chemistry*; D006031:Glycosylation; D006868:Hydrolysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry; D015203:Reproducibility of Results; D020539:Sequence Analysis, Protein / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D006020:Glycopeptides; D009844:Oligosaccharides