Identification of 2-oxohistidine Interacting Proteins Using E. coli Proteome Chips
Jun-Mu Lin1,2, Yu-Ting Tsai3, Yu-Hsuan Liu3
1From the ‡Graduate Institute of Systems Biology and Bioinformatics, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan.
Molecular & Cellular Proteomics : MCP
|September 21, 2016
Summary
Cells possess antioxidant defenses against protein oxidation. Researchers identified ten bacterial proteins that bind to oxidized histidine residues, revealing insights into cellular redox functions and a conserved binding motif.
Area of Science:
- Biochemistry
- Molecular Biology
- Proteomics
Background:
- Cellular proteins face oxidative damage from reactive oxygen species, particularly histidine residues oxidized to 2-oxohistidine.
- Cells may have evolved specific defense mechanisms against this type of protein modification.
Purpose of the Study:
- To identify cellular proteins that specifically interact with the oxidized 2-oxohistidine residue.
- To explore the functional roles and interaction networks of these identified proteins.
- To investigate the evolutionary conservation of binding motifs for oxidized histidine.
Main Methods:
- High-throughput interactome screening using chemically synthesized 2-oxohistidine peptide probes against the E. coli K12 proteome microarray (>4200 proteins).
- Validation of identified protein interactions using additional peptide probes, fluorescence polarization assays, and binding constant measurements.
- Bioinformatic analysis to identify consensus binding motifs and construct functional interaction networks.
Main Results:
- Ten bacterial proteins were identified and validated for their specific interaction with 2-oxohistidine.
- Nine of the ten proteins are involved in redox-related cellular functions, enriched in oxido-reduction processes, ion binding, and carbon metabolism.
- A conserved binding motif was identified in these bacterial proteins and also found in human S100A1 protein, located on α-helices facing outwards.
Conclusions:
- The study successfully identified proteins that bind to oxidized histidine residues, highlighting cellular antioxidant defense strategies.
- The findings reveal a conserved mechanism for recognizing oxidized proteins across species and provide a platform for studying unusual post-translational modifications.
- Proteome microarrays combined with engineered peptide probes are effective for discovering protein interactomes of modified amino acids.
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