Post-Translational Modification Analysis | Sugar Chain Structural Analysis by MSn
Analysis of Glycopeptides Using Data to MS6
The MSn structural analysis of Asn-linked sugar chains is introduced below.
In the MS/MS spectrum obtained using the [M+Na]+(m/z 1999.8) molecular ion peak in the MS spectrum as the precursor ion, the O,2A6 ion(m/z 1562.6) from cross-ring cleavage exhibits the strongest signal. However, at this stage, few product ions can be detected by MS/MS and adequate sugar chain sequence information cannot be obtained.
If an MSn spectrum is obtained using the O,2An ion as the precursor ion, strong signals are expected to be observed for [M-60]+(2,4An ion) and [M-120]+(Bn-1 ion). (See AXIMA QIT Application No. 4.)
Subsequently, sugar chain sequence analysis by MSn was conducted using m/z 1562.6 as the precursor ion.
In the MS3 spectrum obtained with the O,2A6 ion (m/z 1562.6) as the precursor ion, the 2,4A6 ion (m/z 1502.6) and B5 ion (m/z 1442.6) can be observed, as expected. Similarly, in the MS4 spectrum obtained with the B5 ion (m/z 1442.6) as the precursor ion, product ions comprising disaccharides to heptasaccharides were detected.
MS5 with m/z 1077.5 and MS6 with m/z 712.3 were further performed to observe monosaccharide ([Hex or GlcNAc + Na]+) signals. Such a procedure can obtain a large amount of sugar chain structural information from MSn spectra.
Samples supplied by Dr. Yasuhiro Kajihara, International Graduate School of Arts and Sciences, Yokohama City University
- Prominence nano LC permits highly sensitive sugar chain analysis. The unique reflux flow control system enhances separation reproducibility, and the dedicated Nano-Assist software simplifies automation and parameter settings.
- AccuSpot automatically adds the matrix and spots the sugar chains separated by the Prominence nano system onto MALDI plates.
- Separation and purification of sugar chain mixtures by Prominence nano reduces ion suppression by impurities.
- Analysis software provides powerful support for sugar chain structural analysis.