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.

Andrew, Hannah, and Zicong successfully defends his second-year thesis background examination!


Our third-year students are all officially dissertators! Congratulations Dylan, Jericha, Bin, Gutin, Yuan, Graham, Ashley, and Danqing!


Selective Enrichment of Sialylglycopeptides Enabled by Click Chemistry and Dynamic Covalent Exchange

Analytical Chemistry

Despite the important roles of protein sialylation in biological processes such as cellular interaction and cancer progression, simple and effective methods for the analysis of intact sialylglycopeptides (SGPs) are still limited. Analyses of low-abundance SGPs typically require efficient enrichment prior to comprehensive liquid chromatography–mass spectrometry (LC–MS)-based analysis. Here, a novel workflow combining mild periodate oxidation, hydrazide chemistry, copper-catalyzed azide/alkyne cycloaddition (CuAAC) click chemistry, and dynamic covalent exchange has been developed for selective enrichment ...


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...


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...