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April 28, 2026
Gaoyuan (Larry) Lu, Pharmsci graduate student (Li Lab), will be defending his PhD research thesis:
Mass Spectrometry Approaches to Neuropeptidomics and Ion Mobility-Assisted Biomolecular Characterization
Abstract:
This dissertation develops advanced mass spectrometry (MS) and ion mobility–mass spectrometry (IM–MS) strategies across two interconnected research themes: neuropeptidomics and ion mobility-assisted biomolecular chirality analysis. In the first theme, label-free LC–MS/MS peptidomics is applied to map peptidome remodeling in the rat brain following acute cocaine exposure and in the rat spinal cord during chronic osteoarthritis pain, revealing region- and time-specific dysregulation of key neuropeptide families. Extending to invertebrate neuroscience, comprehensive neuropeptidomic profiling of the American lobster (Homarus americanus) identifies novel neuropeptides. Bridging both themes, a multidimensional MS framework discovers three novel D-amino acid-containing peptides in H. americanus and achieves spatial mapping of peptide epimers at the single-neuron and tissue levels. Finally, non-covalent host–guest complexation with a chiral crown ether combined with multi-pass cyclic IMS achieves baseline enantiomeric resolution of amino acids. Collectively, these studies expand neuropeptide landscapes in disease-relevant mammalian and invertebrate systems while establishing versatile IM–MS methodologies for resolving biomolecular stereochemistry.