Performance evaluation on a wide set of matrix‐assisted laser desorption ionization matrices for the detection of oligosaccharides in a high‐throughput mass spectrometric screening of carbohydrate depolymerizing enzymes

Abstract

Compared to other analytical methods, matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) presents several unique advantages for the structural characterization of degradation products of carbohydrates. Our final goal is to implement this technique as a high-throughput platform, with the aim of exploring natural bio-diversity to discover new carbohydrate depolymerizing enzymes. In this approach, a variety of carbohydrates will be used as enzymes substrates and MALDI-MS will be employed to monitor the oligosaccharides produced. One drawback of MALDI, however, is that the choice of the matrix is largely dependent on the chemical properties of the analyte. In this context, our objective in the present work was to find the smallest set of MALDI matrices able to detect chemically heterogeneous oligosaccharides. This was done through the performance evaluation of more than 40 MALDI matrices preparations. Homogeneity of analyte-matrix deposits was considered as a critical feature, especially since the final objective is to fully automate the analyses. Evaluation of the matrices was done by means of a rigorous statistical approach. Amongst all tested compounds, our work proposes the use of the DHB/DMA ionic matrix as the most generic matrix, for rapid detection of a variety of polysaccharides including neutral, anionic, methylated, sulfated, and acetylated compounds. The selected matrices were then used to screen crude bacterial incubation media for the detection of enzymatic degradation products.

New insights into the structural and spatial variability of cell-wall polysaccharides during wheat grain development, as revealed through MALDI mass spectrometry imaging

“…An ionic DHB/DMA matrix that was previously demonstrated to be suitable for the detection of many oligosaccharides (Ropartz et al , 2011) was used in this study. The matrix was prepared as an equimolar mixture of DHB and DMA (DHB 100mg ml –1 in H 2 O/ACN/DMA, 1:1:0.02).…”

Analysis of the dynamic mechanical properties of apple tissue and relationships with the intracellular water status, gas distribution, histological properties and chemical composition

“…Samples were mixed with the ionic liquid matrix DMA/DHB, which was prepared and used as previously reported (Ropartz et al, 2011). Three replicates per hydrolysis were prepared.…”

RNA Interference Suppression of Genes in Glycosyl Transferase Families 43 and 47 in Wheat Starchy Endosperm Causes Large Decreases in Arabinoxylan Content

“…Mass spectra were automatically processed with Flex Analysis 3.0 software (Bruker Daltonics). A mixture of 2,5-dihydroxybenzoic acid and N-dimethylaniline was used as ionic matrix, and samples were prepared as described previously (Ropartz et al, 2011).…”