Functional selection of protease inhibitory antibodies

Area of Science:

• Biochemistry
• Immunology
• Molecular Biology

Background:

• Proteases are crucial for biological processes and represent significant pharmaceutical targets.
• Monoclonal antibodies (mAbs) show promise for inhibiting proteases, but discovery methods focus on binding, not inhibition.
• Identifying inhibitory mAbs is challenging due to limitations in current antibody discovery techniques.

Purpose of the Study:

• To develop a highly efficient selection method for identifying protease inhibitory mAbs.
• To isolate and characterize mAbs targeting diverse protease classes for therapeutic applications.

Main Methods:

• Co-expression of an antibody clone, protease, and a protease-cleavable β-lactamase in *Escherichia coli* for functional selection.
• Antibody-mediated inhibition of protease activity allows cell survival in ampicillin.
• Selection from synthetic human antibody libraries against five protease targets.

Main Results:

• Successfully isolated mAbs inhibiting matrix metalloproteinases (MMP-14, MMP-9), β-secretase 1 (BACE-1), cathepsin B, and Alp2.
• 37 out of 41 identified binders demonstrated inhibitory function.
• Isolated mAbs exhibited nanomolar potency, high selectivity, proteolytic stability, and significant biological activity in cellular and animal models.

Conclusions:

• The developed method is highly efficient for selecting protease inhibitory mAbs.
• The isolated mAbs are potent, selective, and possess therapeutic potential for various diseases.
• This approach advances the discovery of targeted protease inhibitors for research and clinical use.