Engineered botulinum neurotoxin B with improved binding to human receptors has enhanced efficacy in preclinical models.
Elliott, M., Favre-Guilmard, C., Liu, S.M., Maignel, J., Masuyer, G., Beard, M., Boone, C., Carre, D., Kalinichev, M., Lezmi, S., Mir, I., Nicoleau, C., Palan, S., Perier, C., Raban, E., Zhang, S., Dong, M., Stenmark, P., Krupp, J.(2019) Sci Adv 5: eaau7196-eaau7196
- PubMed: 30746458 
- DOI: https://doi.org/10.1126/sciadv.aau7196
- Primary Citation of Related Structures:  
6G5F, 6G5G, 6G5K - PubMed Abstract: 
Although botulinum neurotoxin serotype A (BoNT/A) products are common treatments for various disorders, there is only one commercial BoNT/B product, whose low potency, likely stemming from low affinity toward its human receptor synaptotagmin 2 (hSyt2), has limited its therapeutic usefulness. We express and characterize two full-length recombinant BoNT/B1 proteins containing designed mutations E1191M/S1199Y (rBoNT/B1 MY ) and E1191Q/S1199W (rBoNT/B1 QW ) that enhance binding to hSyt2. In preclinical models including human-induced pluripotent stem cell neurons and a humanized transgenic mouse, this increased hSyt2 affinity results in high potency, comparable to that of BoNT/A. Last, we solve the cocrystal structure of rBoNT/B1 MY in complex with peptides of hSyt2 and its homolog hSyt1. We demonstrate that neuronal surface receptor binding limits the clinical efficacy of unmodified BoNT/B and that modified BoNT/B proteins have promising clinical potential.
Organizational Affiliation: 
Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.