On-MALDI-Target N-Glycan Nonreductive Amination by 2-Aminobenzoic Acid.

2-Aminobenzoic acid (2-AA) is widely used as a labeling reagent to derivatize released N-glycans at their free reducing terminus by reductive amination. 2-AA-labeled glycans have increased mass spectrometric sensitivity for their identification and enable fluorescence-chromatography-based glycan quantification. Drawbacks are that the labeling process is labor intensive and time consuming.

Defining Changes in the Spatial Distribution and Composition of Brain Lipids in the Shiverer and Cuprizone Mouse Models of Myelin Disease.

Myelin is composed primarily of lipids and diseases affecting myelin are associated with alterations in its lipid composition. However, correlation of the spatial (in situ) distribution of lipids with the disease-associated compositional and morphological changes is not well defined. Herein we applied high resolution matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS), immunohistochemistry (IHC), and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) to evaluate brain lipid alterations in the dysmyelinating shiverer (Shi) mouse and cuprizone (Cz) mouse model of reversible demyelination.

Discovery and investigation of O-xylosylation in engineered proteins containing a (GGGGS)n linker.

Protein engineering is a powerful tool for designing or modifying therapeutic proteins for enhanced efficacy, greater safety, reduced immunogenicity, and better delivery. GGGGS [(G4S)n] linkers are commonly used when engineering a protein, because of their flexibility and resistance to proteases. However, post-translational modifications (PTMs) can occur at the Ser residue in these linkers.