Active-site MMP-selective antibody inhibitors discovered from convex paratope synthetic libraries

Significance The matrix metalloproteinase (MMP) family members are promising drug targets in diversified pathologies. Clinical trial failures taught us that selective, rather than broad-specificity, inhibitors are required for successful MMP therapies. Achieving target selectivity with small-molecule MMP inhibitors, however, is exceedingly difficult. Because the antigen-binding sites in conventional antibodies are predominantly incompatible with the concave reaction pockets of MMPs, design of inhibitory antibodies, an attractive alternative for selective inhibition, is also challenging. We synthesized human antibody libraries encoding extended convex antigen-binding sites and isolated a panel of inhibitory Fabs that selectively and efficiently inhibited MMP-14, a promising drug target in cancer. The pipeline we established can now be readily applied for the generation of inhibitory antibodies targeting multiple additional enzymes besides MMPs alone.