Efficient Hydrogen-Deuterium Exchange in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging for Confident Metabolite Identification.
Josiah J RensnerYoung-Jin LeePublished in: Analytical chemistry (2022)
Highly efficient hydrogen-deuterium exchange (HDX) is developed for mass spectrometry imaging (MSI) with low-vacuum matrix-assisted laser desorption/ionization (MALDI). A HDX efficiency of 73-85% is achieved by introducing D 2 O vapor into a heated MALDI source in combination with a deuterium-labeled matrix, which allows correct determination of the number of possible H/D exchanges for up to 17 labile hydrogens. This provides valuable orthogonal information to supplement m / z , allowing for increased confidence in metabolite identification while retaining the spatial information MSI supplies. When combined with high-throughput METASPACE annotation, this approach can systematically improve untargeted metabolite annotations in MALDI-MS imaging. The developed method was applied to MALDI-MS imaging of the top surface, bottom surface, and middle section of Lemna minor fronds. Out of a total of 56 on-sample annotations made with the BraChem database using a 10% false discovery rate, 31 of these annotations (55%) matched our HDX data, providing additional confidence. For the remaining 45%, our data allowed us to narrow down structural possibilities and eliminate incorrect structures, greatly increasing confidence in metabolite identification.
Keyphrases
- mass spectrometry
- high resolution
- liquid chromatography
- capillary electrophoresis
- gas chromatography
- high performance liquid chromatography
- high throughput
- highly efficient
- high resolution mass spectrometry
- small molecule
- ms ms
- computed tomography
- healthcare
- electronic health record
- big data
- pet ct
- social media
- molecularly imprinted
- data analysis
- simultaneous determination