Native Top-Down Mass Spectrometry with Collisionally Activated Dissociation Yields Higher-Order Structure Information for Protein Complexes.
J Am Chem Soc
; 144(48): 21826-21830, 2022 12 07.
Article
em En
| MEDLINE
| ID: mdl-36441927
ABSTRACT
Native mass spectrometry (MS) of proteins and protein assemblies reveals size and binding stoichiometry, but elucidating structures to understand their function is more challenging. Native top-down MS (nTDMS), i.e., fragmentation of the gas-phase protein, is conventionally used to derive sequence information, locate post-translational modifications (PTMs), and pinpoint ligand binding sites. nTDMS also endeavors to dissociate covalent bonds in a conformation-sensitive manner, such that information about higher-order structure can be inferred from the fragmentation pattern. However, the activation/dissociation method used can greatly affect the resulting information on protein higher-order structure. Methods such as electron capture/transfer dissociation (ECD and ETD, or ExD) and ultraviolet photodissociation (UVPD) can produce product ions that are sensitive to structural features of protein complexes. For multi-subunit complexes, a long-held belief is that collisionally activated dissociation (CAD) induces unfolding and release of a subunit, and thus is not useful for higher-order structure characterization. Here we show not only that sequence information can be obtained directly from CAD of native protein complexes but that the fragmentation pattern can deliver higher-order structural information about their gas- and solution-phase structures. Moreover, CAD-generated internal fragments (i.e., fragments containing neither N-/C-termini) reveal structural aspects of protein complexes.
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Base de dados:
MEDLINE
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Projetos de Pesquisa
Idioma:
En
Ano de publicação:
2022
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Article