Li Research Group

Integrated Label-Free and 10-Plex DiLeu Isobaric Tag Quantitative Methods for Profiling Changes in the Mouse Hypothalamic Neuropeptidome and Proteome: Assessment of the Impact of the Gut Microbiome

Analytical Chemistry

Gut microbiota can regulate host physiological and pathological status through gut–brain communications or pathways. However, the impact of the gut microbiome on neuropeptides and proteins involved in regulating brain functions and behaviors is still not clearly understood. To address the problem, integrated label-free and 10-plex DiLeu isobaric tag-based quantitative methods were implemented to compare the profiling of neuropeptides and proteins in the hypothalamus of germ-free (GF)- vs conventionally raised (ConvR)-mice. A total of 2943 endogenous peptides from 63 neuropeptide precursors and...

On-tissue derivatization with Girard’s reagent P enhances N-glycan signals for formalin-fixed paraffin-embedded tissue sections in MALDI mass spectrometry imaging

Analytical Chemistry

Glycosylation is a major protein post-translational modification whose dysregulation has been associated with many diseases. Herein, an on-tissue chemical derivatization strategy based on positively charged hydrazine reagent (Girard’s reagent P) coupled with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was developed for analysis of N-glycans from FFPE treated tissue sections. The performance of the proposed approach was evaluated by analysis of monosaccharides, oligosaccharides, N-glycans released from glycoproteins, as well as MS imaging of N-glycans from human cancer tissue sections. 

Extraction optimization for combined metabolomics, peptidomics, and proteomics analysis of gut microbiota samples

Journal Mass Spectrometry

Multiomic studies are increasingly performed to gain a deeper understanding of molecular processes occurring in a biological system, such as the complex microbial communities (i.e., microbiota) that reside the distal gut. While a combination of metabolomics and proteomics is more commonly used, multiomics studies including peptidomcis characterization are less frequently undertaken. Here, we investigated three different extraction methods, chosen for their previous use in extracting metabolites, peptides, and proteins, and compared their ability to perform metabolomic, peptidomic, and proteomic...

Neuropeptidomic Profiling and Localization in the Crustacean Cardiac Ganglion Using Mass Spectrometry Imaging with Multiple Platforms

Journal of the American  Society of Mass Spectrometry

Urinary Amine Metabolomics Characterization with Custom 12-plex Isobaric DiLeu Labeling

Journal of the American Society for Mass Spectrometry

Urinary metabolomic and proteomic analyses in a mouse model of prostatic inflammation

Urine