Chip electrospray mass spectrometry for carbohydrate analysis

Currently two types of chip systems are used in conjunction with MS: out-of-plane devices, where hundreds of nozzles, nanospray emitters are integrated onto a single silicon substrate from which electrospray is established perpendicular to the substrate, and planar microchips, embedding a microchannel at the end of which electrospray is generated in-plane, on the edge of the microchip. In the last two years, carbohydrate research greatly benefited from the introduction and implementation of the chip-based MS. In two laboratories the advantages of the chip electrospray in terms of ionization efficiency, sensitivity, reproducibility, quality of data in combination with high mass accuracy, and resolution of detection were systematically explored for several carbohydrate classes: O- and N-glycopeptides, oligosaccharides, gangliosides and glycoprotein-derived O- and N-glycans, and glycopeptides. The current state-of-the-art in interfacing the chip electrospray devices to high-performance MS for carbohydrate analysis, and the particular requirements for method optimization in both positive and negative ion modes are reviewed here. The recent applications of these miniaturized devices and their general potential for glycomic-based surveys are highlighted

Thin chip microsprayer system coupled to quadrupole time-of-flight mass spectrometer for glycoconjugate analysis

A thin chip polymer-based microsprayer has been coupled to a hybrid quadrupole time-of-flight mass spectrometer (QTOF MS) and introduced in carbohydrate research. The feasibility of the approach is demonstrated for mapping, sequencing and structural elucidation of glycoconjugates originating from human body fluids and tissues such as a glycopeptide mixture from normal human urine and an isolated and purified GT1 ganglioside fraction from normal adult human brain. The optimization procedure required by each glycoconjugate category is described and the advantages of the system in terms of flexibility and adaptability to QTOF MS, stability of the ESI MS signal, carbohydrate ionization and sequencing, sensitivity, speed of analysis and sample consumption are discussed

Application of the 50% Hydrazine Solution Method for O-Glycans Release, their Chemical Labeling, and HPLC Separation

Mucins are high molecular mass glycoproteins with oligosaccharides O-bonded to the protein core. β-elimination is the most popular method used for releasing of O-glycans. However to such released glycoforms it is difficult to introduce a label to amplify a signal for oligosaccharide detection

Isolation and structural characterization of sialic acid-containing glycopeptides of the O-GlycosidicType from the urine of two patients with an hereditary deliciency in α-N-acetylgalactosaminidase activity

Glycopeptides have been isolated fromthe urine of two patients, aged 5 and 6, with a newlysosomal storage disease characterized by a defi-ciency in α-Ν-acetylgalactosaminidase activity. Isola-tion of these glycopeptides was achieved using gel fil-tration and ion-exchange chromatography. Structuraldetermination was done using one- and two-dimen-sional 500 MHz 1H-NMR spectroscopy and FAB mass spectrometry of native and derivatized glyco-peptides. The following structures were inferred asbeing present: Glycopeptide A (up to 140 mg/l urine)(l)-(3)Neu5Acα2-3Galβ1-3(Neu5Acα2-6)GalNAcα1l- RAl:R = Ser A2:R=Thr A3:R=Thr-ProGlycopeptide Β (up to 80 mg/l urine)(4)-(6)Neu5Acα2-3Galβ1-4GlcNAcβ1-6(Neu5Acα2-3--Galβ1-3)GalNAcα1-R Bl:R = Ser B2:R=Thr B3: R =Thr-Pr