Trypsiligase-Catalyzed Peptide and Protein Ligation

Area of Science:

• Biochemistry
• Chemical Biology
• Protein Engineering

Background:

• Site-specific protein modification is crucial for research but challenging with non-specific chemical methods.
• Enzymatic protein modification offers superior regioselectivity and stereoselectivity.
• Existing methods often lack specificity, leading to heterogeneous products.

Purpose of the Study:

• To present trypsiligase, a trypsin variant, for site-specific protein functionalization.
• To describe general routes for N- or C-terminal protein modification.
• To provide detailed protocols for trypsiligase application and analysis.

Main Methods:

• Utilizing the trypsiligase enzyme for site-specific protein modification.
• Employing two general routes for N- or C-terminal functionalization.
• Synthesizing peptide (ester) substrates and expressing/purifying trypsiligase.

Main Results:

• Achieved homogeneous protein modification exclusively at the desired position.
• Demonstrated rapid reactions under mild conditions.
• Successfully functionalized proteins at either the N- or C-terminus.

Conclusions:

• Trypsiligase is a versatile tool for site-specific protein functionalization.
• This enzymatic approach provides a highly specific and efficient alternative to chemical labeling.
• The described protocols facilitate broad application in protein chemistry research.