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There has been increasing evidence that certain isomeric glycans can be separated efficiently by ion mobility-mass spectrometry when deprotonated ions are analyzed. To better understand the fundamentals behind these separations, we here investigate the impact of ionisation mode and adduct formation using IM-MS, density-functional theory and ab initio molecular dynamics. [ABSTRACT FROM AUTHOR]

Differentiating the structure of isobaric glycopeptides represents a major challenge for mass spectrometry-based characterisation techniques. Here we show that the regiochemistry of the most common N-acetylneuraminic acid linkages of N-glycans can be identified in a site-specific manner from individual glycopeptides using ion mobility-mass spectrometry analysis of diagnostic fragment ions. [ABSTRACT FROM AUTHOR]

We report collision cross sections (CCS) of high-mannose N-glycans as [M + Na]+, [M + K]+, [M + H]+, [M + Cl]−, [M + H2PO4]− and [M − H]− ions, measured by drift tube (DT) ion mobility-mass spectrometry (IM-MS) in helium and nitrogen gases. Further analysis using traveling wave (TW) IM-MS reveal the existence of distinct conformers exclusive to [M − H]− ions. [ABSTRACT FROM AUTHOR]

Carbohydrates are ubiquitous biological polymers that are important in a broad range of biological processes. However, owing to their branched structures and the presence of stereogenic centres at each glycosidic linkage between monomers, carbohydrates are harder to characterize than are peptides and oligonucleotides. Methods such as nuclear magnetic resonance spectroscopy can be used to characterize glycosidic linkages, but this technique requires milligram amounts of material and cannot detect small amounts of coexisting isomers. Mass spectrometry, on the other hand, can provide information on carbohydrate composition and connectivity for even small amounts of sample, but it cannot be used to distinguish between stereoisomers. Here, we demonstrate that ion mobility-mass spectrometry-a method that separates molecules according to their mass, charge, size, and shape-can unambiguously identify carbohydrate linkage-isomers and stereoisomers. We analysed six synthetic carbohydrate isomers that differ in composition, connectivity, or configuration. Our data show that coexisting carbohydrate isomers can be identified, and relative concentrations of the minor isomer as low as 0.1 per cent can be detected. In addition, the analysis is rapid, and requires no derivatization and only small amounts of sample. These results indicate that ion mobility-mass spectrometry is an effective tool for the analysis of complex carbohydrates. This method could have an impact on the field of carbohydrate synthesis similar to that of the advent of high-performance liquid chromatography on the field of peptide assembly in the late 1970s. [ABSTRACT FROM AUTHOR]

Shape-Memory-Alloys (SMA) are suited for miniaturized drives since they possess a high specific workload and scalability. However, most SMA drives still require guidance to realize stiffness. But, there is a design approach for actuators which realize both. Here, the stiffness in the non-moving directions is achieved by the arrangement of the SMA as wire robot. This paper presents a general description of such actuators. Based on that the design of such actuators is formulated as a mathematical optimization algorithm providing a correlation between the variables for design and specification. In order to evaluate this approach, a rotary and a linear actuator are designed and experimentally investigated. [ABSTRACT FROM AUTHOR]