Translocation domain of botulinum neurotoxin A subtype 2 potently induces entry into neuronal cells.
Microbiol Immunol
; 64(7): 502-511, 2020 Jul.
Article
em En
| MEDLINE
| ID: mdl-32301520
ABSTRACT
Botulinum neurotoxin (BoNT) is the causative agent of botulism in humans and animals. Only BoNT serotype A subtype 1 (BoNT/A1) is used clinically because of its high potency and long duration of action. BoNT/A1 and BoNT/A subtype 2 (BoNT/A2) have a high degree of amino acid sequence similarity in the light chain (LC) (96%), whereas their N-and C-terminal heavy chain (HN and HC ) differ by 13%. The LC acts as a zinc-dependent endopeptidase, HN as the translocation domain, and HC as the receptor-binding domain. BoNT/A2 and BoNT/A1 had similar potency in the mouse bioassay, but BoNT/A2 entered faster and more efficiently into neuronal cells. To identify the domains responsible for these characteristics, HN of BoNT/A1 and BoNT/A2 was exchanged to construct chimeric BoNT/A121 and BoNT/A212. After expression in Escherichia coli, chimeric and wild-type BoNT/As were purified as single-chain proteins and activated by conversion to disulfide-linked dichains. The toxicities of recombinant wild-type and chimeric BoNT/As were similar, but dropped to 60% compared with the values of native BoNT/As. The relative orders of SNAP-25 cleavage activity in neuronal cells and toxicity differed. BoNT/A121 and recombinant BoNT/A2 have similar SNAP-25 cleavage activity. BoNT/A2 HN is possibly responsible for the higher potency of BoNT/A2 than BoNT/A1.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Recombinantes
/
Toxinas Botulínicas Tipo A
/
Neurônios
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Microbiol Immunol
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão