Identification and characterization of a novel botulinum neurotoxin

Abstract

Botulinum neurotoxins are known to have seven serotypes (BoNT/A–G). Here we report a new BoNT serotype, tentatively named BoNT/X, which has the lowest sequence identity with other BoNTs and is not recognized by antisera against known BoNTs. Similar to BoNT/B/D/F/G, BoNT/X cleaves vesicle-associated membrane proteins (VAMP) 1, 2 and 3, but at a novel site (Arg66-Ala67 in VAMP2). Remarkably, BoNT/X is the only toxin that also cleaves non-canonical substrates VAMP4, VAMP5 and Ykt6. To validate its activity, a small amount of full-length BoNT/X was assembled by linking two non-toxic fragments using a transpeptidase (sortase). Assembled BoNT/X cleaves VAMP2 and VAMP4 in cultured neurons and causes flaccid paralysis in mice. Thus, BoNT/X is a novel BoNT with a unique substrate profile. Its discovery posts a challenge to develop effective countermeasures, provides a novel tool for studying intracellular membrane trafficking, and presents a new potential therapeutic toxin for modulating secretions in cells.

The role of the single interchains disulfide bond in tetanus and botulinum neurotoxins and the development of antitetanus and antibotulism drugs

“…When expressed in Escherichia coli , the corresponding proteins were not recognised by available standard anti‐BoNT antisera. They were identified in Weissella oryzae (Mansfield et al, ; Zornetta et al, ), in strain 111 of C. botulinum (Sicai Zhang et al, ), in the genome of a strain IDI0629 of Enterococcus faecium (Brunt et al, ; S. Zhang et al, ), and in Cryseobacterium piperi (Mansfield et al, ). Most notably, both the Weissella and the Cryseobacterium sequences lack the SS bond connecting the L and HN domain.…”

Crystal structures of OrfX2 and P47 from a Botulinum neurotoxin OrfX‐type gene cluster

“…The structures did not show any fold similar to the HA cluster proteins. Several of the members have (3) phosphate; PtdIns(4)P, phosphatidylinositol (4) phosphate; PtdIns(5)P, phosphatidylinositol (5) phosphate; PE, phosphatidylethanolamine; PC, phosphatidylcholine; S1P, sphingosine-1-phosphate; PtdIns(3,4) P 2 , phosphatidylinositol (3,4) bisphosphate; PtdIns(3,5)P 2 , phosphatidy linositol (3,5) bisphosphate; PtdIns(4,5)P 2 , phosphatidylinositol (4,5) bisphosphate; PtdIns(3,4,5)P 3 , phosphatidylinositol (3,4,5) trisphosphate; PA, phosphatidic acid; PS, phosphatidylserine; DAG, diacylglycerol; PG, phosphatidylglycerol. 3).…”

Workgroup Report by the Joint Task Force Involving American Academy of Allergy, Asthma & Immunology (AAAAI); Food Allergy, Anaphylaxis, Dermatology and Drug Allergy (FADDA) (Adverse Reactions to Foods Committee and Adverse Reactions to Drugs, Biologicals, and Latex Committee); and the Centers for Disease Control and Prevention Botulism Clinical Treatment Guidelines Workgroup—Allergic Reactions to Botulinum Antitoxin: A Systematic Review

“…Thus, serum antibody raised for antitoxin against one serotype does not cross-react with other serotypes [5]. Recently, reports of new toxin types have been published, including a novel toxin subsequently shown to be hybrid type A/F fully neutralized by heptavalent botulinum antitoxin (HBAT) [6,7], and a novel toxin identified and assembled from the published gene sequence of a C. botulinum isolate [8].…”