フルテキストURL ApplEntomolZool_53_1_63.pdf ApplEntomolZool_53_1_63_fig.pdf
著者 Okazaki, Tomoaki| Ichinose, Junya| Takebe, So| Ide, Toru| Hayakawa, Tohru|
抄録 A Cry46Ab toxin derived from Bacillus thuringiensis strain TK-E6 shows mosquitocidal activity against Culex pipiens pallens Coquillett (Diptera: Culicidae) larvae as well as preferential cytotoxicity against human cancer cells. In B. thuringiensis cells, Cry46Ab is produced and accumulates as a protein crystal that is processed into the active 29-kDa toxin upon solubilization in the alkaline environment of the insect midgut. The Cry46Ab protoxin is 30 kDa, and is therefore thought to require an accessory protein such as P20 and/or ORF2 for efficient crystal formation. In the present study, the potency of the 4AaCter-tag was investigated for the production of alkali-soluble inclusion bodies of recombinant Cry46Ab in Escherichia coli. The 4AaCter-tag is a polypeptide derived from the C-terminal region of the B. thuringiensis Cry4Aa toxin and facilitates the formation of alkali-soluble protein inclusion bodies in E. coli. Fusion with the 4AaCter-tag enhanced both Cry46Ab production and the formation of Cry46Ab inclusion bodies. In addition, upon optimization of protein expression procedures, the Cry46Ab–4AaCter inclusion bodies showed mosquitocidal activity and stability in aqueous environments comparable to Cry46Ab without the 4AaCter-tag. Our study suggests that use of the 4AaCter-tag is a straightforward approach for preparing formulations of smaller-sized Cry toxins such as Cry46Ab in E. coli.
キーワード Bacillus thuringiensis Mosquitocidal Cry46Ab toxin 4AaCter-tag Formation of protein inclusion Escherichia coli
備考 This is an Accepted Manuscript of an article published by Springer Nature
発行日 2018-02
出版物タイトル Applied Entomology and Zoology
53巻
1号
出版者 Springer Japan
開始ページ 67
終了ページ 73
ISSN 0003-6862
NCID AA00543238
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン author
DOI 10.1007/s13355-017-0529-5
Web of Sience KeyUT 000422695600008
関連URL isVersionOf https://doi.org/10.1007/s13355-017-0529-5
フルテキストURL ApplEntomolZool_52_1_61.pdf ApplEntomolZool_52_1_61_fig.pdf ApplEntomolZool_52_1_61_suppl.pdf
著者 Hayakawa, Tohru| Yoneda, Naoya| Okada, Kouji| Higaki, Ayuko| Mohammad Tofazzal Hossain Howlader| Ide, Toru|
抄録 A 2,175-bp modified gene (cry11Ba-S1) encoding Cry11Ba from Bacillus thuringiensis subsp. jegathesan was designed and the recombinant protein was expressed as a fusion protein with glutathione S-transferase in Escherichia coli. The recombinant Cry11Ba was highly toxic against Culex pipiens mosquito larvae, being nine and 17 times more toxic than mosquitocidal Cry4Aa and Cry11Aa from Bacillus thuringiensis subsp. israelensis, respectively. Interestingly, a further increase in the toxicity of the recombinant Cry11Ba was achieved by mixing with Cry4Aa, but not with Cry11Aa. These findings suggested that Cry11Ba worked synergistically with Cry4Aa, but not with Cry11Aa, in exhibiting toxicity against C. pipiens larvae. On the other hand, the amount of Cry toxin bound to brush border membrane vesicles (BBMVs) did not significantly change between individual toxins and the toxin mixtures, suggesting that the increase in toxins binding to BBMVs was not a reason for the observed synergistic effect. It is generally accepted that synergism of toxins is a potentially powerful tool for enhancing insecticidal activity and managing Cry toxin resistance in mosquitoes. The mixture of Cry4Aa and Cry11Ba in order to increase toxicity would be very valuable in terms of mosquito control.
キーワード Cry toxin Synergistic toxicity Insect pest control Biological control Disease vector
備考 This is an Accepted Manuscript of an article published by Springer Nature
発行日 2017-02
出版物タイトル Applied Entomology and Zoology
52巻
1号
出版者 Springer Japan
開始ページ 61
終了ページ 68
ISSN 0003-6862
NCID AA00543238
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン author
DOI 10.1007/s13355-016-0454-z
Web of Sience KeyUT 000394150200007
関連URL isVersionOf https://doi.org/10.1007/s13355-016-0454-z