Protease Inhibitory Abs
Encoded by ~2% of human genome, proteases are important signaling molecules involved in numerous key physiological processes. Consequently, dysregulation of proteolysis is implicated in a variety of diseases, and thus proteases represent one of the largest families of potential pharmaceutical targets. Mounting evidence taught us that specificity is highly desired for any protease inhibition therapy. However, distinguishing proteases using small molecule inhibitors is exceedingly difficult (e.g. fails of board spectrum MMP inhibitors in clinical trials). Antibody-based inhibitors are therefore emerging as promising protease-blocking agents thanks to their exquisite specificity.
By designing and constructing antibody library enriched with convex paratops (PNAS 2016), and developing functional screening methods based on dual color FACS (PEDS 2017), periplasmic FRET assays (B&B 2013), deep DNA sequencing (B&B 2017) and genetic selection (PNAS 2019), we isolated a panel of highly potent and selective inhibitors targeting all four main classes of proteases: matrix metalloproteinases (MMP-14/-9), beta-secretase 1 (BACE1, an aspartic protease), cathepsin K (a cysteine protease), and Alp2 (a fungal serine protease).
We enhanced the stability of our mAbs while retaining their affinity and potency (Protein Sci 2019; B&B 2018). We also changed the selectivity of inhibitory mAbs from one protease to another of the same family (Antib Ther 2018). To establish an efficient research system, we also improved the productions of MMPs (B&B 2016), their natural inhibitory proteins called TIMPs (Microbial Cell Factories 2017), and our isolated mAbs (ABAB 2017). We conducted comprehensive alanine scanning study for full understanding the inhibition mechanisms of inhibitory mAbs (Biochemistry 2020). Overall, highly potent mAb inhibitors with exclusive selectivity have been discovered for many proteases of biomedical importance with the potentials to provide desired therapeutic efficacy.
In melanoma and breast cancer mouse models, anti-MMP14 mAb 3A2 significantly reduced cancer cell spreading and tumor formation at secondary sites (Oncotarget 2017; 2018). Intravenous application of mAb L13, an anti-MMP9 inhibitor with 20 nM potency isolated by genetic selection, exhibited pain attenuation effects in the paclitaxel mouse model (PNAS 2019) and relieved neuropathy in diabetic models. Furthermore, mAbs isolated in my lab also demonstrated treatment efficacy in models of stroke, obesity (Mol Cell Biol 2020; Nat Metab 2022), and SARS-CoV-2.