A Novel Method for Relative Quantitation of N-Glycans by Isotopic Labeling Using 18O-Water

Relative quantification of peptide phosphorylation in a complex mixture using 18O labeling.

We have developed a method to determine the degree of phosphorylation of a peptide in a complex mixture without enrichment or operation of the mass spectrometer in negative ion mode. Yeast lysate containing known amounts of synthetic peptides (VPQLEIVPNSAEERLHSMK and VPQLEIVPN[pS]AEERLHSMK) was labeled with (16)O and (18)O during hydrolysis. After treatment of one sample with a cocktail of phos...

A robust method for quantitative high-throughput analysis of proteomes by 18O labeling.

MS-based quantitative proteomics plays an increasingly important role in biological and medical research and the development of these techniques remains one of the most important challenges in mass spectrometry. Numerous stable isotope labeling approaches have been proposed. However, and particularly in the case of (18)O-labeling, a standard protocol of general applicability is still lacking, a...

A Novel Method for Removal of Hazardous Microplastics from Water Using Magnets

A method for efficient isotopic labeling of recombinant proteins.

A rapid and efficient approach for preparing isotopically labeled recombinant proteins is presented. The method is demonstrated for 13C labeling of the C-terminal domain of angiopoietin-2, 15N labeling of ubiquitin and for 2H/13C/15N labeling of the Escherichia coli outer-membrane lipoprotein Lpp-56. The production method generates cell mass using unlabeled rich media followed by exchange into ...

Rapid Preparation of Released N-Glycans for HILIC Analysis Using a Novel Fluorescence and MS-Active Labeling Reagent

Conventional approaches to the preparation of N-glycans for HILICFLR-MS are either laborious, time-consuming, or require compromises in sensitivity. In the case of one of the most frequently employed labeling compounds, 2-aminobenzamide (2-AB), the resulting glycans can be readily detected by fluorescence but are difficult to detect by electrospray ionization mass spectrometry (ESI-MS). Variati...