Dr. Lingjun Li

Lingjun received her BE degree in Environmental Analytical Chemistry from Beijing Polytechnic University and a PhD degree in Analytical Chemistry/Biomolecular Chemistry from University of Illinois at Urbana-Champaign. She did three-way postdoctoral research at the Pacific Northwest National Laboratory, Brandeis University, and University of Illinois before joining the School of Pharmacy faculty in 2002. She currently holds joint appointments in the School of Pharmacy and Department of Chemistry at UW-Madison, as well as being named Charles Melbourne Johnson Distinguished Chair and Vilas Distinguished Achievement Professor.

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Recent advances in isobaric labeling and applications in quantitative proteomics

Proteomics

Mass spectrometry (MS) has emerged at the forefront of quantitative proteomic techniques. Liquid chromatography-mass spectrometry (LC-MS) can be used to determine abundances of proteins and peptides in complex biological samples. Several methods have been developed and adapted for accurate quantification based on chemical isotopic labeling. Among various chemical isotopic labeling techniques, isobaric tagging approaches rely on the analysis of peptides from MS2-based quantification rather than MS1-based quantification. In this review, we will provide an overview of several isobaric tags along with...

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Comparing Selected-Ion Collision Induced Unfolding with All Ion Unfolding Methods for Comprehensive Protein Conformational Characterization

Journal of the American Society for Mass Spectrometry

Structural analysis by native ion mobility–mass spectrometry provides a direct means to characterize protein interactions, stability, and other biophysical properties of disease-associated biomolecules. Such information is often extracted from collision-induced unfolding (CIU) experiments, performed by ramping a voltage used to accelerate ions entering a trap cell prior to an ion mobility separator. Traditionally, to simplify data analysis and achieve confident ion identification, precursor ion selection with a quadrupole is performed prior to collisional activation...

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Nanosecond Photochemical Reaction for Enhanced Identification, Quantification, and Visualization of Primary Amine-Containing Metabolites by MALDI-Mass Spectrometry

Analytical Chemistry

Many metabolites, including amino acids, neurotransmitters, and pharmaceuticals, contain primary amine functional groups. The analysis of these molecules by mass spectrometry (MS) plays an important role in the study of cancers and psychogenic diseases. However, the MS-based detection and visualization of these bioactive metabolites directly from real biological systems still suffer from challenges such as low ionization efficiency and/or matrix interference effects. Here, we introduce a simple and efficient strategy, the nanosecond photochemical...