Neutral Borate Buffer Activates Diazo for Rapid Protein Labeling

Area of Science:

• Chemical Biology
• Organic Chemistry
• Biochemistry

Background:

• Diazo compounds are carbene precursors for bioorthogonal labeling.
• Existing methods require acidic, metallic, or light activation.
• A need exists for mild, efficient protein modification techniques.

Purpose of the Study:

• To develop a novel boron-diazo chemistry for protein labeling.
• To demonstrate rapid, bioorthogonal carbene generation under physiological conditions.
• To explore applications in drug discovery and disease pathology.

Main Methods:

• Utilized neutral borate buffer to activate diazo compounds.
• Investigated boron-diazo-mediated covalent modification of proteins.
• Applied the chemistry to design covalent inhibitors and label protein aggregates.
• Used the probe in Alzheimer's disease brain tissue for amyloid plaque analysis.

Main Results:

• Boron-diazo chemistry enables carbene generation and protein labeling without external activators.
• Modification occurs rapidly (seconds) under physiological conditions, targeting carboxylate residues.
• Successfully designed a covalent inhibitor for dihydrofolate reductase.
• Captured cellular aggresomes and labeled amyloid plaques in disease models.

Conclusions:

• Boron-diazo chemistry offers a facile and rapid protein modification strategy.
• This method functions under mild, bioorthogonal conditions.
• Demonstrated broad applicability in chemical biology and disease research.