Metabolite fingerprinting by infrared matrix-assisted laser desorption electrospray ionization mass spectrometry

• DOI: 10.1016/j.slast.2025.100272
• Publication Date: 2025-03-13T08:27:46Z
• Authors: Alena N. Joignant; Fan Pu; Shaun M. McLoughlin; James W. Sawicki; Andrew J. Radosevich; Renze Ma; Jon D. Williams; Sujatha M. Gopala...; Nathaniel L. Elsen
• Keywords: Desorption electrospray ionization; Extractive electrospray ionization; Mass spectrometry imaging

The adoption of mass spectrometry for high-throughput screening in drug discovery has become increasingly prevalent and enabled label-free against diverse targets. Cellular assays phenotypic screening, however, are primarily conducted by microscopy as there remain many challenges associated with conducting screens via ultra-high throughput spectrometry. Following a simple on-plate extraction, infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) was employed to directly sample the cell lysate at speed one per second high resolution. A549 cells were treated compounds identified hits literature, including recently reported glutaminase cellular screen. Among test confirmed inhibitors, proposed nuisance compounds, cell-active but enzyme-inactive compounds. Filtered data further processed R dimensionality reduction unsupervised clustering. general nature enables immediate use this method applications other than inhibition. Though we observed that all affected intracellular conversion glutamine glutamate, clear metabolic differences between biochemically active off-target false hits. Moreover, two cluster separately from inhibitors metabolite fingerprints. This proof-of-concept work establishes workflow spectrometry-based screening. methods herein, IR-MALDESI, could offer new avenue novel drugs.