Engineered botulinum neurotoxin B with improved efficacy for targeting human receptors

• DOI: 10.1038/s41467-017-00064-y
• Publication Date: 2017-06-26T22:27:39Z
• Authors: Liang Tao; Lisheng Peng; Ronnie P.-A. Bern...; Sai Man Liu; SunHyun Park; Feifan Yu; Christopher Boone; Shilpa Palan; Matthew Beard; Pierre-Etienne Ch...; Pål Stenmark; Johannes Krupp; Min Dong
• Keywords: Neurotoxin; Saturated mutagenesis; Botulinum neurotoxin; Clostridium botulinum; Botulism

Botulinum neurotoxin B is a Food and Drug Administration-approved therapeutic toxin. However, it has lower binding affinity toward the human version of its major receptor, synaptotagmin II (h-Syt II), compared to mouse Syt II, because residue difference. Increasing h-Syt may improve botulinum B's efficacy reduce adverse effects. Here we utilized bacterial adenylate cyclase two-hybrid method carried out saturation mutagenesis screen in II-binding pocket B. The identifies E1191 as key residue: replacing with M/C/V/Q enhances II. Adding S1199Y/W or W1178Q secondary mutation further increases affinity. Mutant containing E1191M/S1199Y exhibits ~11-fold higher blocking neurotransmission than wild-type neurons expressing demonstrating that enhancing receptor overall at functional levels. engineered provides platform develop toxins improved efficacy.Humans are less sensitive effects (BoNT/B) animal models tested on due differences between receptors. Here, authors engineer BoNT/B receptors enhance efficacy.