title: Binding activity and immunogenic characterization of recombinant C-terminal quarter and half of the heavy chain of botulinum neurotoxin serotype A.
abstract: In the present study, we explored and compared the binding activity and immunogenic characterization of the most effective part corresponding to C-terminal quarter of heavy chain of botulinum neurotoxin serotype A (AHc-C) with C-terminal half of heavy chain of botulinum neurotoxin serotype A (AHc). Firstly, the fully soluble AHc-C protein successfully expressed in Escherichia coli by co-expression with thioredoxin (Trx) was shown to bind with ganglioside as the AHc, indicating that the recombinant AHc-C protein retains a functionally active conformation. Furthermore, a solid-phase assay showed that the anti-AHc-C sera effectively inhibited the binding of AHc or AHc-C to the ganglioside GT1b, the first step in BoNT/A intoxication of neurons, as good as the anti-AHc sera. Finally, although the recombinant AHc-C protein still induced a high serum antibody titers and afforded protection level as the mice challenged with active botulinum neurotoxin serotype A, the immunization with AHc protein induced stronger protective potency than the AHc-C protein. The data presented in the report shows that there are the same ganglioside binding activity and different immunogenic characterization between the C-terminal quarter and half of heavy chain of botulinum neurotoxin serotype A. Therefore, the recombinant AHc-C protein can not only be developed into a minimal subunit candidate vaccine for prophylaxis against botulinum neurotoxin serotype A but also be used as a promising tool in the search for binding inhibitors and chimeric vaccines.
authors.affiliation: Beijing Institute of Biotechnology, Beijing, China.
authors.forename: Yun-Zhou
authors.initials: YZ
authors.lastname: Yu
authors.forename: Yao
authors.initials: Y
authors.lastname: Ma
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Chen
authors.forename: Zheng-Wei
authors.initials: ZW
authors.lastname: Gong
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Wei-Yuan
authors.initials: WY
authors.lastname: Yu
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Sun
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology / Q000378:metabolism; D001904:Botulinum Antitoxin / Q000097:blood / Q000276:immunology / Q000378:metabolism; D019274:Botulinum Toxins, Type A / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D005732:Gangliosides / Q000378:metabolism; D015870:Gene Expression; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000907:Antibodies, Bacterial; D001904:Botulinum Antitoxin; D005732:Gangliosides; D011994:Recombinant Proteins; D019274:Botulinum Toxins, Type A