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

Area of Science:

• Biochemistry
• Chemical Biology
• Proteomics

Background:

• Chemical cross-linking mass spectrometry (XL-MS) is vital for studying protein structure and interactions.
• Existing cross-linkers have limited residue targeting (N-terminus, lysine, glutamate, aspartate, cysteine).

Purpose of the Study:

• To design and characterize a novel bifunctional cross-linker, DBMT, to broaden XL-MS applications.
• To develop a new cross-linking strategy targeting previously inaccessible amino acid residues.

Main Methods:

• Synthesis and characterization of the bifunctional cross-linker DBMT.
• Selective targeting of tyrosine via electrochemical click reaction.
• Selective targeting of histidine via photocatalytic reaction with singlet oxygen (1O2).
• Demonstration using model proteins for XL-MS analysis.

Main Results:

• DBMT selectively targets tyrosine and histidine residues.
• A novel cross-linking strategy using DBMT was successfully developed and validated.
• The method complements existing XL-MS tools for protein analysis.

Conclusions:

• DBMT significantly expands the utility of XL-MS.
• This new cross-linker provides a valuable tool for analyzing protein structure, complexes, interactions, and dynamics.