Targeting of an inhibitory antibody to the catalytic cleft of metalloenzymes
Metalloenzymes are important medicinal targets for conditions ranging from pathogenic infections to cancer. Inhibitory monoclonal antibody (mAb) scaffolds are often used to achieve selective molecular blocking of various metalloenzyme targets. However, antibodies' potency is often limited by the low immunogenicity of functional sites residing in protein clefts. The present technology consists of a novel approach for generating highly potent and selective inhibitory mAbs (metallobodies) targeting functional metallo-sites.
Specific targeting of inhibitory antibodies to enzymatic active sites is invaluable both for research purposes, and as clinical diagnostic and therapeutic reagents. The innovative immunization strategy implemented in the current technology utilizes smart metallo-site mimicry organic molecules, followed by whole metalloenzyme of interest to stimulate affinity maturation towards metal-ion epitope and additional surface epitopes in the context of the whole molecule. This immunization procedure yielded prototype function blocking metallobodies targeting the catalytic zinc ion in matrix metalloproteinase-9 (MMP-9), an enzyme associated with inflammatory conditions and invasion diseases. As it was estimated that over 30% of known proteins require metal cofactors for proper functionality, this approach may provide a wide range of applications.