Updated on 2024/04/17

写真a

 
TSUMURAYA Takeshi
 
Organization
Graduate School of Science Department of Biological Chemistry Professor
School of Science Department of Biological Chemistry
Title
Professor
Affiliation
Institute of Science
Affiliation campus
Nakamozu Campus

Position

  • Graduate School of Science Department of Biological Chemistry 

    Professor  2022.04 - Now

  • School of Science Department of Biological Chemistry 

    Professor  2022.04 - Now

Degree

  • 理学博士 ( University of Tsukuba )

Research Areas

  • Nanotechnology/Materials / Chemical biology

  • Nanotechnology/Materials / Bio chemistry

  • Nanotechnology/Materials / Chemistry and chemical methodology of biomolecules

  • Nanotechnology/Materials / Chemistry and chemical methodology of biomolecules  / 天然物化学

  • Nanotechnology/Materials / Bio chemistry  / タンパク質・酵素化学

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Research Interests

  • transition-state analog

  • directed evolution

  • biofunctional moletule

  • library

  • monoclonal antibody

  • hybridoma

Professional Memberships

  • 酵素工学研究会

    2006.10 - Now   Domestic

  • 日本化学会 フロンティア生命化学研究会

  • THE CHEMICAL SOCIETY OF JAPAN

  • The Japanese Peptide Society

  • コンビナトリアル・バイオエンジニアリング研究会

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Job Career (off-campus)

  • Osaka Metropolitan University   Department of Biological Chemistry, Graduate School of Science

    2022.04 - Now

  • Osaka Prefecture University   Graduate School of Science, Department of Biological Science

    2017.04 - Now

Papers

  • Sensitive Detection of Ciguatoxins Using a Neuroblastoma Cell-Based Assay with Voltage-Gated Potassium Channel Inhibitors

    Toshiaki Yokozeki, Madoka Kawabata, Kazuhiro Fujita, Masahiro Hirama, Takeshi Tsumuraya

    Toxins   16 ( 3 )   118 - 118   2024.02( eISSN:2072-6651

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    Publishing type:Research paper (scientific journal)  

    Ciguatoxins (CTXs) are neurotoxins responsible for ciguatera poisoning (CP), which affects more than 50,000 people worldwide annually. The development of analytical methods to prevent CP is a pressing global issue, and the N2a assay is one of the most promising methods for detecting CTXs. CTXs are highly toxic, and an action level of 0.01 μg CTX1B equivalent (eq)/kg in fish has been proposed. It is desirable to further increase the detection sensitivity of CTXs in the N2a assay to detect such low concentrations reliably. The opening of voltage-gated sodium channels (NaV channels) and blocking of voltage-gated potassium channels (KV channels) are thought to be involved in the toxicity of CTXs. Therefore, in this study, we developed an assay that could detect CTXs with higher sensitivity than conventional N2a assays, using KV channel inhibitors as sensitizing reagents for N2a cells. The addition of the KV channel inhibitors 4-aminopyridine and tetraethylammonium chloride to N2a cells, in addition to the traditional sensitizing reagents ouabain and veratridine, increased the sensitivity of N2a cells to CTXs by up to approximately 4-fold. This is also the first study to demonstrate the influence of KV channels on the toxicity of CTXs in a cell-based assay.

    DOI: 10.3390/toxins16030118

    PubMed

  • Evaluation of relative potency of calibrated ciguatoxin congeners by near-infrared fluorescent receptor binding and neuroblastoma cell-based assays

    Toshiaki Yokozeki, Yuka Hama, Kazuhiro Fujita, Tomoji Igarashi, Masahiro Hirama, Takeshi Tsumuraya

    Toxicon   230   107161 - 107161   2023.07( ISSN:0041-0101

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.toxicon.2023.107161

    PubMed

  • Cell immunolocalization of ciguatoxin-like compounds in the benthic dinoflagellate Gambierdiscus australes M. Chinain & M.A. Faust by confocal microscopy International coauthorship

    120   102353   2022.12( ISSN:15689883

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    DOI: 10.1016/j.hal.2022.102353

    PubMed

  • A smartphone-controlled amperometric immunosensor for the detection of Pacific ciguatoxins in fish Reviewed International coauthorship

    374   2022.04

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    Publishing type:Research paper (scientific journal)   Kind of work:Joint Work   International / domestic magazine:International journal  

    DOI: 10.1016/j.foodchem.2021.131687. Epub 2021 Dec 2.

  • Electrochemical biosensor for the dual detection of Gambierdiscus australes and Gambierdiscus excentricus in field samples. First report of G. excentricus in the Balearic Islands. Reviewed

    Greta Gaiani, Francesca Cucchi, Anna Toldrà, Karl B Andree, María Rey, Takeshi Tsumuraya, Ciara K O'Sullivan, Jorge Diogène, Mònica Campàs

    The Science of the total environment   150915 - 150915   2021.10

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    Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    Several genera of marine dinoflagellates are known to produce bioactive compounds that affect human health. Among them, Gambierdiscus and Fukuyoa stand out for their ability to produce several toxins, including the potent neurotoxic ciguatoxins (CTXs), which accumulate through the food web. Once fishes contaminated with CTXs are ingested by humans, it can result in an intoxication named ciguatera. Within the two genera, only some species are able to produce toxins, and G. australes and G. excentricus have been highlighted to be the most abundant and toxic. Although the genera Gambierdiscus and Fukuyoa are endemic to tropical areas, their presence in subtropical and temperate regions has been recently recorded. In this work, the combined use of species-specific PCR primers for G. australes and G. excentricus modified with short oligonucleotide tails allowed the development of a multiplex detection system for these two toxin-producing species. Simultaneous detection was achieved using capture probes specific for G. australes and G. excentricus immobilized on maleimide-coated magnetic beads (MBs), separately placed on the working electrodes of a dual electrode array. Additionally, a rapid DNA extraction technique based on a portable bead beater system and MBs was developed, significantly reducing the extraction time (from several hours to 30 min). The developed technique was able to detect as low as 10 cells of both Gambierdiscus species and allowed the first detection of G. excentricus in the Balearic Islands in 8 out of the 12 samples analyzed. Finally, field samples were screened for CTXs with an immunosensor, successfully reporting 13.35 ± 0.5 pg CTX1B equiv. cell-1 in one sample and traces of toxins in 3 out of the 9 samples analyzed. These developments provide rapid and cost-effective strategies for ciguatera risk assessment, with the aim of guaranteeing seafood safety.

    DOI: 10.1016/j.scitotenv.2021.150915

    PubMed

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Books and Other Publications

  • 酵素の反応速度解析「バイオサイエンス実験:入門から応用へ」

    藤井 郁雄,円谷 健,藤原 大佑( Role: Joint author)

    大阪公立大学共同出版会  2016.04 

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    Responsible for pages:89-107  

  • タンパク質の定量「バイオサイエンス実験:入門から応用へ」

    藤井 郁雄,円谷 健,藤原 大佑( Role: Joint author)

    大阪公立大学共同出版会  2016.04 

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    Responsible for pages:25-32  

  • パパイン処理による抗体のFabの調製

    円谷健,藤井郁雄( Role: Joint author)

    NTS  2012.08 

  • 抗体酵素ーテーラーメイド人工酵素の創出

    円谷健,藤井郁雄( Role: Joint author)

    NTS  2012.08 

  • 新しいくすりづくり:ケミカルバイオロジー

    藤井郁雄,円谷健,藤原大佑,多田俊治,木下誉富,恩田真紀,切畑光統,谷森紳治,神川憲,乾隆( Role: Joint author)

    NTS  2011.12 

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    Responsible for pages:257-273  

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Presentations

  • An approach to ciguatera research based on anti-ciguatoxin monoclonal antibodies Invited International conference

    Takeshi Tsumuraya

    International Symposium in Okinawa, 2023, on Ciguatera and Related Marine Biotoxins: Post symposium of the ICHA2023 Hiroshima  2023.11  Organizing committee of International Symposium in Okinawa, 2023, on Ciguatera and Related Marine Biotoxins

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    Presentation type:Oral presentation (invited, special)  

  • Evaluation of differences in acid stability of ciguatoxin congeners from the Pacific by LC-MS/MS International conference

    Toshiaki Yokozeki, Kazuhiro Fujita, Tomoji Igarashi, Masahiro Hirama, Takeshi Yasumoto, Takeshi Tsumuraya

    The 20th International Conference on Harmful Algae (ICHA2023)  2023.11  International Society for the Study of Harmful Algae

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    Presentation type:Poster presentation  

  • Development of purification method for ciguatoxins in fish using lipid hydrolysis and application to near-infrared fluorescent receptor binding assay International conference

    Toshiaki Yokozeki, Kazuhiro Fujita, Tomoji Igarashi, Takeshi Tsumuraya, Takeshi Yasumoto

    International Symposium in Okinawa, 2023, on Ciguatera and Related Marine Biotoxins: Post symposium of the ICHA2023 Hiroshima  2023.11  Organizing committee of International Symposium in Okinawa, 2023, on Ciguatera and Related Marine Biotoxins: Post symposium of the ICHA2023 Hiroshima

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    Presentation type:Poster presentation  

  • Evaluation of relative potency of calibrated ciguatoxin congeners by near-infrared fluorescent receptor binding and neuroblastoma cell-based assays International conference

    Toshiaki Yokozeki, Yuka Hama, Kazuhiro Fujita, Tomoji Igarashi, Masahiro Hirama, Takeshi Tsumuraya

    International Symposium in Okinawa, 2023, on Ciguatera and Related Marine Biotoxins: Post symposium of the ICHA2023 Hiroshima  2023.11  Organizing committee of International Symposium in Okinawa, 2023, on Ciguatera and Related Marine Biotoxins: Post symposium of the ICHA2023 Hiroshima

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    Presentation type:Poster presentation  

  • Evaluation of Relative Potency of Calibrated Ciguatoxin Congeners by Near-infrared Fluorescent Receptor Binding and Neuroblastoma Cell-based Assays Domestic conference

    2023.09 

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    Presentation type:Oral presentation (general)  

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Grant-in-Aid for Scientific Research

  • Development of Caribbean ciguatoxin-specific antibodies for prevention and treatment of ciguatera

    Grant-in-Aid for Scientific Research(C)  2024

Charge of on-campus class subject

  • 生物化学実験2

    2024   Weekly class   Undergraduate

  • 基礎有機化学

    2024   Weekly class   Undergraduate

  • ケミカルバイオロジー特論

    2024   Weekly class   Graduate school

  • 生物化学特別研究2A

    2024   Intensive lecture   Graduate school

  • 生物化学特別研究1A

    2024   Intensive lecture   Graduate school

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Charge of off-campus class subject

  • 科学英語

    Institution:Osaka Prefecture University

  • 社会に生きる科学

    Institution:Osaka Prefecture University

  • 生物科学課題実験

    Institution:Osaka Prefecture University

  • 生物科学演習II

    Institution:Osaka Prefecture University

  • 生物科学演習I

    Institution:Osaka Prefecture University

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Media Coverage

  • 朝日新聞 Newspaper, magazine

    2019.04

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    シガテラ食中毒およびシガテラ食中毒原因毒素の検出に関して,朝日新聞 アピタルで専門家としてコメントした.(4/16, 17, 18, 19に掲載)

Visiting Lectures ⇒ Link to the list of Visiting Lectures

  • どのようにして食べてはいけない魚を見分けるのか?

    Category:Science (mathematics, physics, chemistry, biology, geology, biochemistry), Agricultural science (applied biology, biofunctional chemistry, green space environmental science)

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    Audience:Junior high school students, High school students, College students, Teachers, Researchers, General, Company, Civic organization

    Keyword:シガテラ 微量検出 バイオテクノロジー モノクローナル抗体 

    バイオテクノロジーを用いたシガテラ毒の微量検出法の開発について講義する.