A tyrosine, histidine-selective bifunctional cross-linker for protein structure analysis

Chemical cross-linking mass spectrometry (XL-MS) significantly contributes to the analysis of protein structures and the elucidation of protein-protein interactions. Currently available cross-linkers mainly target N-terminus, lysine, glutamate, aspartate, and cysteine residues in protein. Herein, a bifunctional cross-linker, named [4,4'(disulfanediylbis(ethane-2,1-diyl)) bis(1-methyl-1,2,4-triazolidine-3,5-dione)] (DBMT) has been designed and characterized aiming to extremely expand the application of XL-MS approach. DBMT is capable of selectively targeting tyrosine residue in protein via an electrochemical click reaction, and/or targeting histidine residue in protein in the presence of 1O2 generated under photocatalytic reaction. A novel cross-linking strategy based on this cross-linker has been developed and demonstrated using model proteins, which provides a complementary XL-MS tool analyzing protein structure, protein complexes, protein-protein interactions, and even protein dynamics.

Automated summary

Chemical cross-linking mass spectrometry (XL-MS) is significant in analyzing protein structures and protein-protein interactions. A bifunctional cross-linker, named DBMT, has been designed and characterized to expand the application of XL-MS approach. DBMT can selectively target tyrosine and histidine residues in proteins through electrochemical click reaction and photocatalytic reaction, respectively. A novel cross-linking strategy based on DBMT has been developed and demonstrated using model proteins, which provides a comprehensive XL-MS tool for analyzing protein structure, protein complexes, protein-protein interactions, and even protein dynamics.