Updated on 2022/04/12

写真a

 
SAWADA Yasuyuki
 
Organization
Institutes of Innovation for Future Society Associate professor
Title
Associate professor

Degree 1

  1. Ph.D ( 2012.10   Nagoya University ) 

Research Interests 1

  1. Biophysics

Research Areas 1

  1. Life Science / Biophysics

Research History 4

  1. Nagoya University   Designated associate professor

    2020.10

  2. Nagoya Keizai University   Associate professor

    2017.4 - 2020.9

  3. Nagoya University   Designated assistant professor

    2013.4 - 2017.3

  4. Nagoya University   Researcher

    2010.4 - 2013.3

Education 3

  1. Nagoya University

    2006.4 - 2010.3

  2. Nagoya University

    2004.4 - 2006.3

  3. Waseda University

    2000.4 - 2004.3

 

Papers 4

  1. Biophysical Mechanisms of Membrane-Thickness-Dependent MscL Gating: An All-Atom Molecular Dynamics Study

    Katsuta Hiroki, Sawada Yasuyuki, Sokabe Masahiro

    LANGMUIR   Vol. 35 ( 23 ) page: 7432 - 7442   2019.6

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    Language:Japanese   Publisher:Langmuir  

    The bacterial mechanosensitive channel, MscL, is activated by membrane tension, acting as a safety valve to prevent cell lysis against hypotonic challenge. It has been established that its activation threshold decreases with membrane thickness, while the underlying mechanism remains to be solved. We performed all-atom molecular dynamics (MD) simulations for the initial opening process of MscL embedded in four different types of lipid bilayers with different thicknesses: 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC)), 1,2-dimyristoyl-glycero-3-phosphorylcholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). In response to membrane stretching, channel opening occurred only in the thinner membranes (DLPC and DMPC) in a thickness-dependent way. We found that the MscL opening was governed by the rate and degree of membrane thinning and that the channel opening was tightly associated with the tilting of transmembrane (TM) helices of MscL toward the membrane plane. Upon membrane stretching, the order parameter of acyl chains of thinner membranes (DLPC and DMPC) became smaller, whereas other thicker membranes (DPPC and DSPC) showed interdigitation with little changes in the order parameter. The decreased order parameter contributed much more to membrane thinning than did interdigitation. We conclude that the membrane-thickness-dependent MscL opening mainly arises from structural changes in MscL to match the altered membrane thickness by stretching.

    DOI: 10.1021/acs.langmuir.8b02074

    Web of Science

    Scopus

    PubMed

  2. Corynebacterium glutamicum mechanosensitive channels: towards unpuzzling "glutamate efflux" for amino acid production.

    Nakayama Y, Hashimoto KI, Sawada Y, Sokabe M, Kawasaki H, Martinac B

    Biophysical reviews   Vol. 10 ( 5 ) page: 1359 - 1369   2018.10

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    Language:English   Publisher:Biophysical Reviews  

    Corynebacterium glutamicum has been utilized for industrial amino acid production, especially for monosodium glutamate (MSG), the food-additive for the “UMAMI” category of taste sensation, which is one of the five human basic tastes. Glutamate export from these cells is facilitated by the opening of mechanosensitive channels in the cell membrane within the bacterial cell envelope following specific treatments, such as biotin limitation, addition of Tween 40 or penicillin. A long-unsolved puzzle still remains how and why C. glutamicum mechanosensitive channels are activated by these treatments to export glutamate. Unlike mechanosensitive channels in other bacteria, these channels are not simply osmotic safety valves that prevent these bacteria from bursting upon a hypo-osmotic shock. They also function as metabolic valves to continuously release glutamate as components of a pump-and-leak mechanism regulating the cellular turgor pressure. Recent studies have demonstrated that the opening of the mechanosensitive channel, MscCG, mainly facilitates the efflux of glutamate and not of other amino acids and that the “force-from-lipids” gating mechanism of channels also applies to the MscCG channel. The bacterial types of mechanosensitive channels are found in cell-walled organisms from bacteria to land plants, where their physiological functions have been specialized beyond their basic function in bacterial osmoregulation. In the case of the C. glutamicum MscCG channels, they have evolved to function as specialized glutamate exporters.

    DOI: 10.1007/s12551-018-0452-1

    Scopus

    PubMed

  3. Molecular Dynamics Study for Exploring the Force Transmission Pathway in the Bacterial Mechanosensitive Channel MscL

    Sawada Yasuyuki, Nomura Takeshi, Sokabe Masahiro

    BIOPHYSICAL JOURNAL   Vol. 114 ( 3 ) page: 111A - 111A   2018.2

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  4. Molecular Dynamics Analysis on the Force Transmission Pathway via Inter-Subunit Pathway for Mechano-Gating of Bacterial Mechanosensitive Channel MscL

    Sawada Yasuyuki, Nomura Takeshi, Sokabe Masahiro

    BIOPHYSICAL JOURNAL   Vol. 112 ( 3 ) page: 533A - 533A   2017.2

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KAKENHI (Grants-in-Aid for Scientific Research) 1

  1. 食形態決定のための居宅用流動性測定器の開発と誤嚥性肺炎予防プログラムの構築

    Grant number:21K11094  2021.4 - 2024.3

    科学研究費助成事業  基盤研究(C)

    宇田川 孝子, 山中 崇, 福井 郁子, 高橋 徹, 澤田 康之, 福田 久子, 海老名 慧

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    Authorship:Coinvestigator(s) 

    高齢者の肺炎の7割以上が誤嚥性肺炎であり(Teramoto)、現状のままでは誤嚥性肺炎による死亡者は、更に増加すると予測されている(都健康安全研究センター)。また医療計画の見直しが必要な疾患とされ、予防が急務である。これまで誤嚥性肺炎の予防として、様々な増粘液状食品が開発されてきた。しかし、それら増粘液状食品における従来の物性測定機器では、流動性、分離性の情報が乏しく、最適な食形態の確立は困難である。本研究では、実際の消化管環境での物性の詳細が測定可能な流動性測定器を開発して誤嚥と流動性、分離性との関係を示す。その上で誤嚥性肺炎の予防に最適な食形態の確立を目指した予防プログラムの提案を目指す。