Glycans MALDI

Example The PSD-MALDI-TOF spectrum of the [M+Na]" ion, m/z 1418.9, of high-mannose A-linked glycan (Man)6(GlcNAc)2 from chicken ovalbumin recorded from DHB shows distinct cleavages of the branched carbohydrate skeleton (Fig. 10.16). [134]... 

E. Stephens, S. L. Maslen, L. G. Green, and D. H. Williams, Fragmentation characteristics of neutral V-linked glycans using a MALDI-TOF/TOF tandem mass spectrometer, Anal. Chem., 76 (2004) 2343-2354. 

M. V. Novotny, Y. Huang, and Y. Mechref, Microscale nonreductive release of O-linked glycans for subsequent analysis through MALDI mass spectrometry and capillary electrophoresis, Anal. Chem., 73 (2001) 6063-6069. 

Recent detection methods for glycan array include fluorescent assay, SPR, MALDI-TOF mass spectrometry, and nanoparticle assay. Fluorescence-based measurement is the prevalent principle for detecting binding to glycan microarrays. Rhodamine [9],... 

Fig. 17. MALDI-TOFMS of O-glycans enriched by a standard glycoblotting protocol using ammonium carbamate from human-milk OPN. Numbers represent the peaks attributable to O-glycans labeled with benzyloxyamine (BOA), and an asterisk indicates the internal standard. The glycan compositions listed in Table I were estimated from measured masses of the glycans by use of the GlycoSuite database. This figure is adapted from ref. 96.

Fig. 21. Photograph of the SweetBlot machine, an automated glycan-processing system based on the glycoblotting method. This prototype machine is the latest version, designed for eventual combination with MALDI-TOFMS.

Our ongoing target is the development of fully automated glycan analysis and structural profiling systems, by combining SweetBlot and such versatile mass spectrometers as MALDI-TOFMS and other analytical methods used in general... 

M. Guillard, J. Gloerich, H. J. C. T. Wessels, E. Morava, R. A. Wevers, and D. J. Lefeber, Automated measurement of permethylated serum A-glycans by MALDI-linear ion trap mass spectrometry, Carbohydr. Res., 344 (2009) 1550-1557. 

AA-Ac labeled glycans also give excellent results in MALDI-MS and on current ion-trap instruments detailed MS" studies can be performed with sub-picomole samples. The combination of this analysis with fractionation of complex samples on EIR or amide HPLC is particularly useful allowing reliable quantitation of the AA-Ac tagged glycans by HPLC and detailed structural characterization by MS" fragmentation. 

Nevertheless an appreciation of FAB research is very helpful because the fragmentation pathways observed in FAB spectra are recapitulated in MALDI and ESI experiments. Moreover, many current glycomic protocols have been adapted from FAB-based methodologies developed in the 1980s and 1990s to study complex mixtures of glycans isolated from cells and tissues [14,15,16,17,18]. 

MALDI-MS profiles of the wildtype (panel A) and knockout (panel B) mouse spleen. Putative stnictures based on knowledge ef JV-glycan biosynthetic pathways and glycan cempesition are shown. For convenience enly ene branching pattern for tii-antennaiy structures is shewn. Menesaccharide symbols are shewn in O Table 1... 

To complement the glycoproteomics data, the IgG iV-glycans were released, and profiled by MALDI-TOF MS using fhe glycomics strategy described above (O Fig. 10). 

MALDI-MS spectrum of released JV-glycans from human IgG. Monosaccharide symbols are shown in O Table 1... 

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