Esterase activity of carbonic anhydrases serves as surrogate for selecting antibodies blocking hydratase activity

Area of Science:

• Biochemistry
• Enzymology
• Cancer Biology

Background:

• Carbonic anhydrase 9 (CA9) and carbonic anhydrase 12 (CA12) are validated targets for cancer therapy.
• Development of therapeutic antibodies against CA9 and CA12 is hindered by a lack of specific inhibitors and efficient screening methods.
• Existing screening methods do not adequately assess the inhibition of the hydratase activity crucial for CA9 and CA12 function.

Purpose of the Study:

• To develop a high-throughput screening system for identifying antibodies that inhibit carbonic anhydrase 9 (CA9) and carbonic anhydrase 12 (CA12).
• To establish a surrogate assay that measures esterase activity as a proxy for the hydratase activity of CA9 and CA12.
• To facilitate the discovery of novel therapeutic antibodies targeting CA9 and CA12 for cancer treatment.

Main Methods:

• Utilized the esterase activity of carbonic anhydrases as a surrogate marker for their hydratase activity.
• Developed and validated a robust and cost-effective screening assay for antibody candidates.
• Assessed the ability of identified antibodies to inhibit both esterase and hydratase activities of CA9 and CA12.

Main Results:

• Demonstrated that measuring esterase activity is a reliable method for screening CA9 and CA12 inhibitors.
• Successfully identified antibody candidates that effectively block both esterase and hydratase activities.
• The developed assay provides a facile and efficient approach for early-stage antibody discovery.

Conclusions:

• Measuring carbonic anhydrase esterase activity offers a practical surrogate screening method for identifying therapeutic antibodies.
• This approach overcomes previous bottlenecks in discovering antibodies that inhibit the clinically relevant hydratase activity of CA9 and CA12.
• The study presents the first facile surrogate-screening assay for potential therapeutic antibodies targeting CA9 and CA12.