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Proximity-enhanced SuFEx chemical cross-linker for specific and multitargeting cross-linking mass spectrometry.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America . 10/30/2018, Vol. 115 Issue 44, p11162-11167. 6p. - Publication Year :
- 2018
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Abstract
- Chemical cross-linking mass spectrometry (CXMS) is being increasingly used to study protein assemblies and complex protein interaction networks. Existing CXMS chemical cross-linkers target only Lys, Cys, Glu, and Asp residues, limiting the information measurable. Here we report a "plant-and-cast" cross-linking strategy that employs a heterobifunctional cross-linker that contains a highly reactive succinimide ester as well as a less reactive sulfonyl fluoride. The succinimide ester reacts rapidlywith surface Lys residues "planting" the reagent at fixed locations on protein. The pendant aryl sulfonyl fluoride is then "cast" across a limited range of the protein surface, where it can react with multiple weakly nucleophilic amino acid sidechains in a proximityenhanced sulfur-fluoride exchange (SuFEx) reaction. Using proteins of known structures, we demonstrated that the heterobifunctional agent formed cross-links between Lys residues and His, Ser, Thr, Tyr, and Lys sidechains. This geometric specificity contrasts with current bis-succinimide esters, which often generate nonspecific cross-links between lysines brought into proximity by rare thermal fluctuations. Thus, the current method can provide diverse and robust distance restraints to guide integrative modeling. This work provides a chemical cross-linker targeting unactivated Ser, Thr, His, and Tyr residues using sulfonyl fluorides. In addition, this methodology yielded a variety of cross-links when applied to the complex Escherichia coli cell lysate. Finally, in combination with genetically encoded chemical crosslinking, cross-linking using this reagent markedly increased the identification of weak and transient enzyme-substrate interactions in live cells. Proximity-dependent cross-linking will dramatically expand the scope and power of CXMS for defining the identities and structures of protein complexes. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00278424
- Volume :
- 115
- Issue :
- 44
- Database :
- Academic Search Index
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 132799557
- Full Text :
- https://doi.org/10.1073/pnas.1813574115