Targeted, Site-specific quantitation of N- and O-glycopeptides using O-labeling and product ion based mass spectrometry.

The site-specific quantitation of N- and O-glycosylation is vital to understanding the function(s) of different glycans expressed at a given site of a protein under physiological and disease conditions. Most commonly used precursor ion intensity based quantification method is less accurate and other labeled methods are expensive and require enrichment of glycopeptides. Here, we used glycopeptide product (y and Y0) ions and O-labeling of C-terminal carboxyl group as a strategy to obtain quantitative information about fold-change and relative abundance of most of the glycoforms attached to the glycopeptides.

Structure of a heterogeneous, glycosylated, lipid-bound, in vivo-grown protein crystal at atomic resolution from the viviparous cockroach Diploptera punctata.

Macromolecular crystals for X-ray diffraction studies are typically grown in vitro from pure and homogeneous samples; however, there are examples of protein crystals that have been identified in vivo. Recent developments in micro-crystallography techniques and the advent of X-ray free-electron lasers have allowed the determination of several protein structures from crystals grown in cellulo. Here, an atomic resolution (1.

High throughput proteomic analysis and a comparative review identify the nuclear chaperone, Nucleophosmin among the common set of proteins modulated in Chikungunya virus infection.

Unlabelled: Global re-emergence of Chikungunya virus (CHIKV) has renewed the interest in its cellular pathogenesis. We subjected CHIKV-infected Human Embryo Kidney cells (HEK293), a widely used cell-based system for CHIKV infection studies, to a high throughput expression proteomics analysis by Liquid Chromatography-tandem mass spectrometry. A total of 1047 differentially expressed proteins were identified in infected cells, consistently in three biological replicates.