engleski

Microfluidics/mass spectrometry for glycolipidomics in biomedical research

Advanced mass spectrometry (MS) has the potential to provide key answers addressing structure-to-function relationship for various bio-glycoconjugates, role(s) of glycosylation(s) in regulation of cell physiological processes as well as implications of aberrant glycosylation in cell pathology and/or transformation. In the past decade, capillary nanoelectrospray ionization (nanoESI) MS developed as an effective tool in glycomics. However, the disadvantages of the method include low sample throughput, potential sample carryover and, in some cases, poor reproducibility due to a variable shape of the spaying capillary tip. The recent introduction of chip-based nano- and microESI in biological MS is driven by the high-performance, effeciency, throughput, sensitivity, and speed of analysis. The analytical potential of these assemblies were lately largely proven in proteomics, direct bioanalyses of drugs, drug development, and small molecule characterization. For the MS ionization/separation of quantity-limited complex glycoconjugate mixtures derived from biological matrices, our group implemented in the last few years several novel methodologies based on microfluidics and lab-on-a-chip systems. In this study microfluidic ESI systems operating in the negative ion mode, in combination with Fourier-transform ion cyclotron resonance (FT-ICR) at 9.4 Tesla and hybrid quadroupole time-of-flight (QTOF) tandem mass spectrometry (MS/MS), are introduced for detailed glycolipidome determination in biomedical research. Two different chip ESI systems: a fully automated chip-based nanoESI robot and a thin-chip microsprayer have been coupled each to both QTOF MS and FT-ICR MS. The feasibility of both chip MS approaches was tested for the determination of ganglioside differential expression in human brain regions and elucidation of the region-specific structures. The obtained data indicate that the high sensitivity and ionization eficiency provided at nano-and microscale level by the chip MS infusion in combination with tandem MS make this new approach ideal for studies aiming the detection and structural identification of yet unknown and minor species in complex native mixtures of brain gangliosides.

mass spectrometry; microfluidics; glycolipidomics

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