Covalent Protein Labeling by Enzymatic Phosphocholination

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Protein modification is crucial for biological research and therapeutic applications.
• Existing protein labeling methods often lack specificity or require complex procedures.
• Enzymatic approaches offer precise and efficient protein functionalization.

Purpose of the Study:

• To introduce a new, efficient, and specific protein labeling method.
• To utilize enzymatic phosphocholination for covalent protein modification.
• To enable the attachment and removal of functional moieties on proteins.

Main Methods:

• Employing the bacterial enzyme AnkX from Legionella pneumophila for phosphocholination.
• Utilizing synthetically produced CDP-choline derivatives as phosphocholine donors.
• Demonstrating labeling at N-termini, C-termini, and internal protein regions.
• Employing the Legionella enzyme Lem3 for hydrolytic removal of the modification.

Main Results:

• Successful covalent enzymatic phosphocholination of intact proteins.
• Efficient labeling achieved using a short, specific octapeptide sequence.
• Demonstrated site-specific modification at various protein locations.
• Established hydrolytic removal of the phosphocholine modification.

Conclusions:

• The developed method provides a versatile tool for protein labeling and functionalization.
• Enzymatic phosphocholination offers a specific and efficient alternative to traditional labeling techniques.
• The ability to remove the modification adds a layer of control for experimental design.