Multistage Ultraviolet Photodissociation Mass Spectrometry To Characterize Single Amino Acid Variants of Human Mitochondrial BCAT2
Unraveling disease mechanisms requires a comprehensive understanding of how the interplay between higher-order structure and protein–ligand interactions impacts the function of a given protein. Recent advances in native mass spectrometry (MS) involving multimodal or higher-energy activation methods...
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Published in | Analytical chemistry (Washington) Vol. 90; no. 16; pp. 9904 - 9911 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
21.08.2018
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Subjects | |
Online Access | Get full text |
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Summary: | Unraveling disease mechanisms requires a comprehensive understanding of how the interplay between higher-order structure and protein–ligand interactions impacts the function of a given protein. Recent advances in native mass spectrometry (MS) involving multimodal or higher-energy activation methods have allowed direct interrogation of intact protein complexes in the gas phase, allowing analysis of both composition and subunit connectivity. We report a multistage approach combining collisional activation and 193 nm ultraviolet photodissociation (UVPD) to characterize single amino acid variants of the human mitochondrial enzyme branched-chain amino acid transferase 2 (BCAT2), a protein implicated in chemotherapeutic resistance in glioblastoma tumors. Native electrospray ionization confirms that both proteins exist as homodimers. Front-end collisional activation disassembles the dimers into monomeric subunits that are further interrogated using UVPD to yield high sequence coverage of the mutated region. Additionally, holo (ligand-bound) fragment ions resulting from photodissociation reveal that the mutation causes destabilization of the interactions with a bound cofactor. This study demonstrates the unique advantages of implementing UVPD in a multistage MS approach for analyzing intact protein assemblies. |
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ISSN: | 0003-2700 1520-6882 |
DOI: | 10.1021/acs.analchem.8b02099 |