Updated on 2024/12/23

写真a

 
IDE Toru
 
Organization
Faculty of Interdisciplinary Science and Engineering in Health Systems Professor
Position
Professor
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Degree

  • doctor (science) ( 1992.3   Osaka University )

  • PhD ( 1992.3   Osaka University )

Research Interests

  • channel protein

  • single molecule measurement

Research Areas

  • Life Science / Biophysics  / channel protein

Education

  • Osaka University   基礎工学研究科  

    1985.4 - 1991.9

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  • Kyoto University   理学部  

    1980.4 - 1985.3

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Research History

  • 岡山大学大学院ヘルスシステム統合科学研究科   教授

    2018.4

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  • Okayama University   Faculty of Engineering   Professor

    2013.8

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Papers

  • Mutational analysis of the transmembrane α4-helix of Bacillus thuringiensis mosquito-larvicidal Cry4Aa toxin. International journal

    Hirokazu Takahashi, Mami Asakura, Toru Ide, Tohru Hayakawa

    Current microbiology   81 ( 3 )   80 - 80   2024.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    Cry4Aa, produced by Bacillus thuringiensis subsp. israelensis, exhibits specific toxicity to larvae of medically important mosquito genera. Cry4Aa functions as a pore-forming toxin, and a helical hairpin (α4-loop-α5) of domain I is believed to be the transmembrane domain that forms toxin pores. Pore formation is considered to be a central mode of Cry4Aa action, but the relationship between pore formation and toxicity is poorly understood. In the present study, we constructed Cry4Aa mutants in which each polar amino acid residues within the transmembrane α4 helix was replaced with glutamic acid. Bioassays using Culex pipiens mosquito larvae and subsequent ion permeability measurements using symmetric KCl solution revealed an apparent correlation between toxicity and toxin pore conductance for most of the Cry4Aa mutants. In contrast, the Cry4Aa mutant H178E was a clear exception, almost losing its toxicity but still exhibiting a moderately high conductivity of about 60% of the wild-type. Furthermore, the conductance of the pore formed by the N190E mutant (about 50% of the wild-type) was close to that of H178E, but the toxicity was significantly higher than that of H178E. Ion selectivity measurements using asymmetric KCl solution revealed a significant decrease in cation selectivity of toxin pores formed by H178E compared to N190E. Our data suggest that the toxicity of Cry4Aa is primarily pore related. The formation of toxin pores that are highly ion-permeable and also highly cation-selective may enhance the influx of cations and water into the target cell, thereby facilitating the eventual death of mosquito larvae.

    DOI: 10.1007/s00284-023-03602-8

    PubMed

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  • Random Mutational Analysis Targeting Residue K155 within the Transmembrane β-Hairpin of the Mosquitocidal Mpp46Ab Toxin

    Midoka Miyazaki, Mami Asakura, Toru Ide, Tohru Hayakawa

    Biology   12 ( 12 )   1481 - 1481   2023.12

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    Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Mpp46Ab is a mosquito-larvicidal pore-forming toxin derived from Bacillus thuringiensis TK-E6. Pore formation is believed to be a central mode of Mpp46Ab action, and the cation selectivity of the channel pores, in particular, is closely related to its mosquito-larvicidal activity. In the present study, we constructed a mutant library in which residue K155 within the transmembrane β-hairpin was randomly replaced with other amino acid residues. Upon mutagenesis and following primary screening using Culex pipiens mosquito larvae, we obtained 15 mutants in addition to the wild-type toxin. Bioassays using purified proteins revealed that two mutants, K155E and K155I, exhibited toxicity significantly higher than that of the wild-type toxin. Although increased cation selectivity was previously reported for K155E channel pores, we demonstrated in the present study that the cation selectivity of K155I channel pores was also significantly increased. Considering the characteristics of the amino acids, the charge of residue 155 may not directly affect the cation selectivity of Mpp46Ab channel pores. Replacement of K155 with glutamic acid or isoleucine may induce a similar conformational change in the region associated with the ion selectivity of the Mpp46Ab channel pores. Mutagenesis targeting the transmembrane β-hairpin may be an effective strategy for enhancing the ion permeability of the channel pores and the resulting mosquito-larvicidal activity of Mpp46Ab.

    DOI: 10.3390/biology12121481

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  • 単一イオンチャンネルの簡便計測システム

    Minako HIRANO, Mami ASAKURA, Toru IDE

    Seibutsu Butsuri   63 ( 2 )   110 - 114   2023

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    Publishing type:Research paper (scientific journal)   Publisher:Biophysical Society of Japan  

    DOI: 10.2142/biophys.63.110

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  • Kastor and Polluks polypeptides encoded by a single gene locus cooperatively regulate VDAC and spermatogenesis

    Shintaro Mise, Akinobu Matsumoto, Keisuke Shimada, Toshiaki Hosaka, Masatomo Takahashi, Kazuya Ichihara, Hideyuki Shimizu, Chisa Shiraishi, Daisuke Saito, Mikita Suyama, Tomoharu Yasuda, Toru Ide, Yoshihiro Izumi, Takeshi Bamba, Tomomi Kimura-Someya, Mikako Shirouzu, Haruhiko Miyata, Masahito Ikawa, Keiichi Nakayama

    NATURE COMMUNICATIONS   13 ( 1 )   2022.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:NATURE PORTFOLIO  

    A number of testes-specific lncRNAs have been annotated but their roles remain largely unexplored. Here the authors identify two small peptides encoded by the lncRNA Gm9999, Kastor and Polluks, both of which are required for male fertility in mice.Although several long noncoding RNAs (lncRNAs) have recently been shown to encode small polypeptides, those in testis remain largely uncharacterized. Here we identify two sperm-specific polypeptides, Kastor and Polluks, encoded by a single mouse locus (Gm9999) previously annotated as encoding a lncRNA. Both Kastor and Polluks are inserted in the outer mitochondrial membrane and directly interact with voltage-dependent anion channel (VDAC), despite their different amino acid sequences. Male VDAC3-deficient mice are infertile as a result of reduced sperm motility due to an abnormal mitochondrial sheath in spermatozoa, and deficiency of both Kastor and Polluks also severely impaired male fertility in association with formation of a similarly abnormal mitochondrial sheath. Spermatozoa lacking either Kastor or Polluks partially recapitulate the phenotype of those lacking both. Cooperative function of Kastor and Polluks in regulation of VDAC3 may thus be essential for mitochondrial sheath formation in spermatozoa and for male fertility.

    DOI: 10.1038/s41467-022-28677-y

    Web of Science

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  • Characteristics of channel pores formed by Bacillus thuringiensis mosquito-larvicidal Cry4Aa toxin

    Yuri Shiraishi, Tomoya Shiozaki, Mami Asakura, Toru Ide, Tohru Hayakawa

    Applied Entomology and Zoology   57 ( 1 )   63 - 70   2021.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Cry4Aa toxin produced by Bacillus thuringiensis subsp. israelensis exhibits specific toxicity to larvae of medically important mosquito genera. In the present study, we analyzed the characteristics of channel pores formed by recombinant Cry4Aa in a solvent-free planar lipid bilayer. Stable channel currents were observed in electrophysiologic measurements, and the single-channel conductance was 187 +/- 10 pS in symmetrical buffer containing 150 mM KCl. The channel pores formed by Cry4Aa were cation-selective, with an estimated P-K/P-Cl permeability ratio of 4.9. In addition, Cry4Aa channel pores exhibited apparent cation preference in the order Na+ > K+, Na+ > Ca2+, and K+ > Ca2+. Although the effect was limited, the cation preference of Cry4Aa channel pores seemed to be correlated with toxicity. Culex pipiens mosquito larvae reared in NaCl solution exhibited greater sensitivity to Cry4Aa, particularly early period after exposure. The presence of cations that preferentially translocate through Cry4Aa channel pores may facilitate excessive influx of water into the midgut cells, leading to colloid-osmotic lysis. Whereas CaCl2 had some effect on the mosquito-larvicidal activity of Cry4Aa, KCl had no effect. The effect of some cations may be mitigated by the variety of ion channels present on the midgut cell membrane.

    DOI: 10.1007/s13355-021-00762-6

    Web of Science

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    Other Link: https://link.springer.com/article/10.1007/s13355-021-00762-6/fulltext.html

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MISC

  • 新規な殺蚊Cry46Abトキシンの殺虫活性メカニズム

    早川徹, 榊原暁, 武部聡, 井出徹

    日本応用動物昆虫学会大会講演要旨   63rd   2019

  • 非常に強い殺蚊活性を示すCry11Baトキシンの作用機構

    新谷彩子, 白石優里, 汐崎友哉, 井出徹, 早川徹

    日本分子生物学会年会プログラム・要旨集(Web)   42nd   2019

  • 殺蚊トキシンCry4Aaが形成するチャネルポアの性状

    白石優里, 小薗寛人, 宮崎美登香, 新谷彩子, 井出徹, 早川徹

    日本分子生物学会年会プログラム・要旨集(Web)   42nd   2019

  • ハイブリッドフォトディテクタ(HPD)による広視野高時間分解能生体1分子蛍光検出

    深澤宏仁, 中野学, 長澤貴康, 平野美奈子, 井出徹, 横田浩章

    レーザ顕微鏡研究会講演会抄録集   44th   2019

  • 殺蚊トキシンCry46Abの小孔形成と殺虫活性

    早川徹, 宮崎美登香, 榊原暁, 原田翔也, 朝倉真実, 井出徹

    日本分子生物学会年会プログラム・要旨集(Web)   42nd   2019

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Presentations

  • Development of a simple single-channel current measurement system

    Tomomi Murata, Toru Ide, Minako Hirano, Mami Asakura

    The 61th Annual Meeting of the Biophysical Society of Japan  2023.11 

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  • Identification of Key Amino Acids affecting the Activity of Photoactivated Adenylyl Cyclase from Oscillatoria acuminata

    Minako Hirano, Masumi Takebe, Syunshi Yano, Hinase Kondo, Ayu Yuasa, Toru Ide

    The 61th Annual Meeting of the Biophysical Society of Japan  2023.11 

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  • Development of channel current measurement device using agarose gel beads

    Mami Asakura, Shuyan Wang, Minako Hirano, Toru Ide

    The 61th Annual Meeting of the Biophysical Society of Japan  2023.11 

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  • Structural changes of adenylate cyclase from Oscillatoria acuminata in response to blue light stimulation

    Yuki Kitamura, Toru Ide, Minako Hirano

    The 60th Annual Meeting of the Biophysical Society of Japan  2022.9 

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  • Current status of low-light photodetectors capable of detecting near-infrared light

    Atsuhito Fukasawa, Minako Hirano, Toru Ide, Hiroaki Yokota

    2022.9 

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Industrial property rights

  • 人工生体膜を製造するデバイス及び製造方法

    平野 美奈子, 井出 徹

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    Applicant:学校法人光産業創成大学院大学

    Application no:特願2015-154014  Date applied:2015.8.4

    Announcement no:特開2017-029090  Date announced:2017.2.9

    Patent/Registration no:特許第6632826号  Date registered:2019.12.20 

    J-GLOBAL

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Awards

  • Hot Article Award Analytical Sciences

    2016.12   Analytical Sciences  

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  • 2012 Research Paper Award

    Rebeiz Foundation for Basic Research  

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  • Hiroshi and Aya Irisawa Memorial Award for Excellent Papers in The Journal of Physiological Sciences

    Simultaneous optical and electrical recording of a single ion-channel

    Toru Ide, Yuko Takeuchi, Takaaki Aoki, Toshio Yanagida

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Research Projects

  • ハイスループット単一チャネル電流記録装置の開発

    Grant number:22K06169  2022.04 - 2025.03

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    井出 徹

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    Grant amount:\4160000 ( Direct expense: \3200000 、 Indirect expense:\960000 )

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  • Single molecule measurement of ligand bindings to the acetylcholine receptor channel

    Grant number:18K06157  2018.04 - 2022.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    井出 徹

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    Grant amount:\4420000 ( Direct expense: \3400000 、 Indirect expense:\1020000 )

    本研究の目的は1分子蛍光計測と単一チャネル電流記録を同時に可能とすることである。前年度までの研究成果をもとに、引き続き要素技術の改良と装置全体の整合を行った。
    i)光学系(単一チャネル電流記録法と金属増強蛍光計測の融合):前年度までに開発した1分子観察用蛍光顕微鏡を改良、汎用性を高め、目的であるアセチルコリン受容体チャネルの計測に最適化した。
    ii)プローブ(電極):本研究では、金属電極表面に固定したチャネル蛋白を直接人工膜に挿入する新しい電流計測法を用いている。昨年度に引き続き、試行錯誤しながら電極先端の形状等の作製条件を改良した。昨年度までは、先端が鋭利な金線、市販の金属ナノ粒子(金ナノロッド等)を蛍光増強に利用してきたが、使用可能な蛍光励起波長帯を広げるため銀電極の使用を検討した。電解研磨法の溶液・電流条件を検討することによって先端の曲率半径が100nm以下の金・銀電極を再現良く作製することが可能となった。また、実験に使用する人工膜の安定性を高めるため、電極表面の修飾法についても検討した。電極表面を疎水性分子で修飾することにより人工膜を著しく安定化させることに成功した。
    さらに副次的な成果として、上記の電流計測法を用いたイオンチャネル蛋白の高効率測定装置の開発も手がけた。金属、あるいは親水性ゲル表面に固定したチャネル蛋白を透過するイオン性電流を高効率で測定する自動計測装置の開発に成功した。これについては前年度既に報告済であるが、装置を改良し、より高効率化することに成功した。これらの測定装置を用いて、土壌細菌によるタンパク毒(Bacillus thuringiensisによるCryToxin)がイオンチャネルを形成することを発見し、それらのチャネル活性の解析も行った。

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  • Development of a single molecule sensor with a novel method for artificial bilayer measurements.

    Grant number:15K13725  2015.04 - 2018.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research  Grant-in-Aid for Challenging Exploratory Research

    Ide Toru

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    Grant amount:\3900000 ( Direct expense: \3000000 、 Indirect expense:\900000 )

    The purpose of this study was to make a novel bio-sensor using artificial bilayers formed on the surface of a gold electrode.
    (1) Improvements of conventional method for bilayer formation: We have developed the method for bilayer formation at water/metal interface. The surface of a gold electrode was modified with hydrophilic polymers. A stable artificial bilayer was formed just by moving the tip through a lipid solution layer. Using this bilayer, we measured single channel current fluctuations of channel forming peptides such as gramicidin.(2) Protein incorporation: Ion channel proteins were immobilized on the surface of the gold electrode and these were inserted into the bilayer. The channels were incorporated into the bilayer almost simaltaneously with bilayer formation at the interface. We measured single channel currents of several types of human channel proteins using this method.

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  • Development of High-throughput Platform for Ion Channel Analysis Using Artificial Cell Membrane Systems

    Grant number:25246017  2013.04 - 2017.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)  Grant-in-Aid for Scientific Research (A)

    Takeuchi Shoji, SATO Koji, IDE Toru

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    Grant amount:\45630000 ( Direct expense: \35100000 、 Indirect expense:\10530000 )

    In this study, we developed a high-throughput platform for analyses of ion channel functions. A cell membrane model was artificially reconstructed on a microchip, in which we optimized the efficiency and reproducibility of the membrane formation and integrated the number of the membrane on a single chip. Accordingly, we examined reconstitution techniques of ion channels into the membrane on the chip, and finally verified the developed platform using functional assays of drug-target ion channels. The results demonstrated the feasibility of our platform, especially for precise ion channel analyses with a single-molecule level. Based on the developed technologies, we continuously improve the performance of the platform, hoping for practical use in drug screening of ion channels.

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  • Study on structure-function relationship of KcsA channel by single molecule manipulation.

    Grant number:24657110  2012.04 - 2014.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research  Grant-in-Aid for Challenging Exploratory Research

    IDE Toru

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    Grant amount:\4160000 ( Direct expense: \3200000 、 Indirect expense:\960000 )

    Our purpose was to develop an apparatus for simulataneous mechanical manipulation and optical recording of single ion channel protein, KcsA, by which we measure inter- and intra-molecule interactions that activate the channel. We have succeeded in (1)single molecule manipulation of KcsA immobilized at the tip of a fine glass needle (2)developing a technique for mechanically incorporating the KcsA into an artificial bilayer (3)making the measurement efficiency much higher than conventional methods by optimizing experimental conditions.

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Class subject in charge

  • BioNanoTechnology (2024academic year) Third semester  - 月1~2

  • General Biotechnology and Drug Discovery Technology (2024academic year) Prophase  - 木1~2

  • Advanced Internship for Interdisciplinary Medical Sciences and Engineering (2024academic year) Year-round  - その他

  • Technical English for Interdisciplinary Medical Sciences and Engineering (2024academic year) Late  - その他

  • Research Works for Interdisciplinary Medical Sciences and Engineering (2024academic year) Year-round  - その他

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