A single backbone amide modification method to achieve single site-specific chemical protein conjugation

Area of Science:

• Biotechnology
• Chemical Biology
• Protein Engineering

Background:

• Chemical protein modification is crucial for biotechnology.
• Site-specific modification of large proteins remains a significant challenge.
• Existing methods often lack efficiency and precision.

Purpose of the Study:

• To introduce a novel method for site-specific protein modification.
• To demonstrate the efficiency and accuracy of the new technique.
• To showcase its application in creating antibody-drug conjugates.

Main Methods:

• Development of the Copper Assisted Sequence-specific Conjugation Tag (CAST) method.
• Utilizing sequence-specific tags for targeted chemical modification.
• Assessment of reaction kinetics and site specificity.
• Preparation and evaluation of antibody-drug conjugates.

Main Results:

• The CAST method achieves rapid (second order rate 8.1 M⁻¹s⁻¹) and site-specific protein backbone modification.
• Antibody-drug conjugates prepared using CAST exhibit high plasma stability.
• Demonstrated potent efficacy of CAST-derived conjugates in vitro and in vivo.
• CAST provides an efficient and quantitative approach for payload conjugation.

Conclusions:

• CAST is an efficient and quantitative method for site-specific chemical modification of large, native proteins.
• The method enables precise payload attachment, crucial for applications like antibody-drug conjugates.
• CAST offers a versatile tool for advancing biotechnology and drug development.