Updated on 2025/01/07

写真b

 
TAISHI Kasai
 
*Items subject to periodic update by Rikkyo University (The rest are reprinted from information registered on researchmap.)
Affiliation*
College of Science
Title*
Assistant Professor
Campus Career*
  • 4 2023 - Present 
    College of Science   Assistant Professor
  • 4 2018 - 3 2023 
    College of Science   Department of Life Science   Assistant Professor
 

Research Areas

  • Life Science / Applied microbiology

Research History

  • 4 2018 - Present 
    RIKKYO UNIVERSITY   College of Science Department of Life Science   Assistant Professor

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  • 7 2015 - 3 2018 
    法政大学マイクロナノテクノロジー研究センター

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  • 4 2015 - 6 2015 
    大阪市立大学   大学院理学研究科

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Education

  • - 3 2015 
    Osaka City University   Graduate School, Division of Natural Science

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    Country: Japan

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  • - 3 2012 
    Osaka City University   Graduate School, Division of Natural Science

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    Country: Japan

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  • - 3 2010 
    Osaka City University   Faculty of Science

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    Country: Japan

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Papers

  • FtsZ of wall-less bacteria forms ring-like structures

    Taishi Kasai, Yohei O Tahara, Makoto Miyata, Daisuke Shiomi

        16 10 2024

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    Publisher:Cold Spring Harbor Laboratory  

    Abstract

    The FtsZ protein is involved in bacterial cell division. In cell-walled bacteria, such asBacillus subtilis, FtsZ forms a ring-like structure, called the Z ring, at the cell division site and acts as a scaffold for cell wall synthesis. The inhibition of cell wall synthesis inB. subtilishas been shown to interfere with the function of the Z ring, causing a loss in cell division control.Spiroplasma, a cell wall-less bacterium, lacks most of the genes involved in cell division; however, theftsZgene remains conserved. The function ofSpiroplasma eriocheirisFtsZ (SeFtsZ) remains to be determined. In the present study, we analyzed the biochemical characteristics of SeFtsZ. Purified SeFtsZ demonstrated lower polymerization capacity and GTPase activity than FtsZ fromE. coliandB. subtilis. We also investigated the relationship between SeFtsZ and SeSepF, which anchors FtsZ to the cell membrane, and found that SeSepF did not contribute to the stability of FtsZ filaments, unlike theB. subtilisSepF. SeFtsZ and SeSepF were produced inE. coliL-forms, where cell wall synthesis was inhibited. SeFtsZ formed ring-like structures in cell wall-lessE. colicells, suggesting that SeFtsZ forms Z rings and is involved in cell division independently of cell wall synthesis.

    DOI: 10.1101/2024.10.15.618391

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  • Relationship between the Rod complex and peptidoglycan structure in Escherichia coli. International journal

    Risa Ago, Yuhei O Tahara, Honoka Yamaguchi, Motoya Saito, Wakana Ito, Kaito Yamasaki, Taishi Kasai, Sho Okamoto, Taiki Chikada, Taku Oshima, Issey Osaka, Makoto Miyata, Hironori Niki, Daisuke Shiomi

    MicrobiologyOpen12 ( 5 ) e1385   10 2023

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

    Peptidoglycan for elongation in Escherichia coli is synthesized by the Rod complex, which includes RodZ. Although various mutant strains of the Rod complex have been isolated, the relationship between the activity of the Rod complex and the overall physical and chemical structures of the peptidoglycan have not been reported. We constructed a RodZ mutant, termed RMR, and analyzed the growth rate, morphology, and other characteristics of cells producing the Rod complexes containing RMR. The growth and morphology of RMR cells were abnormal, and we isolated suppressor mutants from RMR cells. Most of the suppressor mutations were found in components of the Rod complex, suggesting that these suppressor mutations increase the integrity and/or the activity of the Rod complex. We purified peptidoglycan from wild-type, RMR, and suppressor mutant cells and observed their structures in detail. We found that the peptidoglycan purified from RMR cells had many large holes and different compositions of muropeptides from those of WT cells. The Rod complex may be a determinant not only for the whole shape of peptidoglycan but also for its highly dense structure to support the mechanical strength of the cell wall.

    DOI: 10.1002/mbo3.1385

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  • Motility Assays of Mycoplasma mobile Under Light Microscopy. International journal

    Taishi Kasai, Makoto Miyata

    Methods in molecular biology (Clifton, N.J.)2646   321 - 325   2023

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

    Mycoplasma mobile forms a membrane protrusion at a pole as an organelle. M. mobile cells bind to solid surfaces and glide in the direction of the protrusion. In gliding motility, M. mobile cells catch, pull and release sialylated oligosaccharides on host cells. The observation of Mycoplasma species under light microscopy is useful for the analysis of adhesion ability and the motility mechanism.

    DOI: 10.1007/978-1-0716-3060-0_26

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  • Movements of Mycoplasma mobile Gliding Machinery Detected by High-Speed Atomic Force Microscopy. International journal

    Kohei Kobayashi, Noriyuki Kodera, Taishi Kasai, Yuhei O Tahara, Takuma Toyonaga, Masaki Mizutani, Ikuko Fujiwara, Toshio Ando, Makoto Miyata

    mBio12 ( 3 ) e0004021   29 6 2021

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

    Mycoplasma mobile, a parasitic bacterium, glides on solid surfaces, such as animal cells and glass, by a special mechanism. This process is driven by the force generated through ATP hydrolysis on an internal structure. However, the spatial and temporal behaviors of the internal structures in living cells are unclear. In this study, we detected the movements of the internal structure by scanning cells immobilized on a glass substrate using high-speed atomic force microscopy (HS-AFM). By scanning the surface of a cell, we succeeded in visualizing particles, 2 nm in height and aligned mostly along the cell axis with a pitch of 31.5 nm, consistent with previously reported features based on electron microscopy. Movements of individual particles were then analyzed by HS-AFM. In the presence of sodium azide, the average speed of particle movements was reduced, suggesting that movement is linked to ATP hydrolysis. Partial inhibition of the reaction by sodium azide enabled us to analyze particle behavior in detail, showing that the particles move 9 nm right, relative to the gliding direction, and 2 nm into the cell interior in 330 ms and then return to their original position, based on ATP hydrolysis. IMPORTANCE The Mycoplasma genus contains bacteria generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide by a special mechanism linked to their infection and survival. The special machinery for gliding can be divided into surface and internal structures that have evolved from rotary motors represented by ATP synthases. This study succeeded in visualizing the real-time movements of the internal structure by scanning from the outside of the cell using an innovative high-speed atomic force microscope and then analyzing their behaviors.

    DOI: 10.1128/mBio.00040-21

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  • Direct Observation of Conversion From Walled Cells to Wall-Deficient L-Form and Vice Versa in Escherichia coli Indicates the Essentiality of the Outer Membrane for Proliferation of L-Form Cells. International journal

    Taiki Chikada, Tomomi Kanai, Masafumi Hayashi, Taishi Kasai, Taku Oshima, Daisuke Shiomi

    Frontiers in microbiology12   645965 - 645965   2021

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

    Gram-negative bacteria such as Escherichia coli are surrounded by an outer membrane, which encloses a peptidoglycan layer. Even if thinner than in many Gram-positive bacteria, the peptidoglycan in E. coli allows cells to withstand turgor pressure in hypotonic medium. In hypertonic medium, E. coli treated with a cell wall synthesis inhibitor such as penicillin G form wall-deficient cells. These so-called L-form cells grow well under anaerobic conditions (i.e., in the absence of oxidative stress), becoming deformed and dividing as L-form. Upon removal of the inhibitor, they return to the walled rod-shaped state. Recently, the outer membrane was reported to provide rigidity to Gram-negative bacteria and to strengthen wall-deficient cells. However, it remains unclear why L-form cells need the outer membrane for growth. Using a microfluidic system, we found that, upon treatment with the outer membrane-disrupting drugs polymyxin B and polymyxin B nonapeptide or with the outer membrane synthesis inhibitor CHIR-090, the cells lysed during cell deformation and division, indicating that the outer membrane was important even in hypertonic medium. L-form cells could return to rod-shaped when trapped in a narrow space, but not in a wide space, likely due to insufficient physical force. Outer membrane rigidity could be compromised by lack of outer membrane proteins; Lpp, OmpA, or Pal. Deletion of lpp caused cells to lyse during cell deformation and cell division. In contrast, ompA and pal mutants could be deformed and return to small oval cells even when less physical force was exerted. These results strongly suggest that wall-deficient E. coli cells require a rigid outer membrane to survive, but not too rigid to prevent them from changing cell shape.

    DOI: 10.3389/fmicb.2021.645965

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  • 生態,生理・構造,遺伝・ゲノミクス・バイオテクノロジー 高速原子間力顕微鏡が捕らえた! マイコプラズマモービレ滑走装置の動き(Movement of Gliding Motors in Mycoplasma mobile Visualized by High-speed Atomic Force Microscopy)

    小林 昂平, 古寺 哲幸, 田原 悠平, 豊永 拓真, 笠井 大司, 安藤 敏夫, 宮田 真人

    日本細菌学雑誌74 ( 1 ) 39 - 39   3 2019

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    Language:English   Publisher:日本細菌学会  

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  • Measurements of the Rotation of the Flagellar Motor by Bead Assay. International journal

    Taishi Kasai, Yoshiyuki Sowa

    Methods in molecular biology (Clifton, N.J.)1593   185 - 192   2017

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

    The bacterial flagellar motor is a reversible rotary nano-machine powered by the ion flux across the cytoplasmic membrane. Each motor rotates a long helical filament that extends from the cell body at several hundreds revolutions per second. The output of the motor is characterized by its generated torque and rotational speed. The torque can be calculated as the rotational frictional drag coefficient multiplied by the angular velocity. Varieties of methods, including a bead assay, have been developed to measure the flagellar rotation rate under various load conditions on the motor. In this chapter, we describe a method to monitor the motor rotation through a position of a 1 μm bead attached to a truncated flagellar filament.

    DOI: 10.1007/978-1-4939-6927-2_14

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  • Gliding Direction of Mycoplasma mobile. International journal

    Hanako Morio, Taishi Kasai, Makoto Miyata

    Journal of bacteriology198 ( 2 ) 283 - 90   15 1 2016

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

    UNLABELLED: Mycoplasma mobile glides in the direction of its cell pole by a unique mechanism in which hundreds of legs, each protruding from its own gliding unit, catch, pull, and release sialylated oligosaccharides fixed on a solid surface. In this study, we found that 77% of cells glided to the left with a change in direction of 8.4° ± 17.6° μm(-1) displacement. The cell body did not roll around the cell axis, and elongated, thinner cells also glided while tracing a curved trajectory to the left. Under viscous conditions, the range of deviation of the gliding direction decreased. In the presence of 250 μM free sialyllactose, in which the binding of the legs (i.e., the catching of sialylated oligosaccharides) was reduced, 70% and 30% of cells glided to the left and the right, respectively, with changes in direction of ∼30° μm(-1). The gliding ghosts, in which a cell was permeabilized by Triton X-100 and reactivated by ATP, glided more straightly. These results can be explained by the following assumptions based on the suggested gliding machinery and mechanism: (i) the units of gliding machinery may be aligned helically around the cell, (ii) the legs extend via the process of thermal fluctuation and catch the sialylated oligosaccharides, and (iii) the legs generate a propulsion force that is tilted from the cell axis to the left in 70% and to the right in 30% of cells. IMPORTANCE: Mycoplasmas are bacteria that are generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide. Although these species appear to consistently glide in the direction of the protrusion, their exact gliding direction has not been examined. This study analyzed the gliding direction in detail under various conditions and, based on the results, suggested features of the machinery and the mechanism of gliding.

    DOI: 10.1128/JB.00499-15

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  • Gliding Motility of Mycoplasma mobile on Uniform Oligosaccharides Peer-reviewed International journal

    Taishi Kasai, Tasuku Hamaguchi, Makoto Miyata

    JOURNAL OF BACTERIOLOGY197 ( 18 ) 2952 - 2957   9 2015

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER SOC MICROBIOLOGY  

    The binding and gliding of Mycoplasma mobile on a plastic plate covered by 53 uniform oligosaccharides were analyzed. Mycoplasmas bound to and glided on only 21 of the fixed sialylated oligosaccharides (SOs), showing that sialic acid is essential as the binding target. The affinities were mostly consistent with our previous results on the inhibitory effects of free SOs and suggested that M. mobile recognizes SOs from the nonreducing end with four continuous sites as follows. (i and ii) A sialic acid at the nonreducing end is tightly recognized by tandemly connected two sites. (iii) The third site is recognized by a loose groove that may be affected by branches. (iv) The fourth site is recognized by a large groove that may be enhanced by branches, especially those with a negative charge. The cells glided on uniform SOs in manners apparently similar to those of the gliding on mixed SOs. The gliding speed was related inversely to the mycoplasma's affinity for SO, suggesting that the detaching step may be one of the speed determinants. The cells glided faster and with smaller fluctuations on the uniform SOs than on the mixtures, suggesting that the drag caused by the variation in SOs influences gliding behaviors.
    IMPORTANCE
    Mycoplasma is a group of bacteria generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide in the direction of the protrusion. These procedures are essential for parasitism. Usually, mycoplasmas glide on mixed sialylated oligosaccharides (SOs) derived from glycoprotein and glycolipid. Since gliding motility on uniform oligosaccharides has never been observed, this study gives critical information about recognition and interaction between receptors and SOs.

    DOI: 10.1128/JB.00335-15

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  • Role of binding in Mycoplasma mobile and Mycoplasma pneumoniae gliding analyzed through inhibition by synthesized sialylated compounds. International journal

    Taishi Kasai, Daisuke Nakane, Hideharu Ishida, Hiromune Ando, Makoto Kiso, Makoto Miyata

    Journal of bacteriology195 ( 3 ) 429 - 35   2 2013

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

    Mycoplasmas, which have been shown to be the causative pathogens in recent human pneumonia epidemics, bind to solid surfaces and glide in the direction of the membrane protrusion at a pole. During gliding, the legs of the mycoplasma catch, pull, and release sialylated oligosaccharides fixed on a solid surface. Sialylated oligosaccharides are major structures on animal cell surfaces and are sometimes targeted by pathogens, such as influenza virus. In the present study, we analyzed the inhibitory effects of 16 chemically synthesized sialylated compounds on the gliding and binding of Mycoplasma mobile and Mycoplasma pneumoniae and concluded the following. (i) The recognition of sialylated oligosaccharide by mycoplasma legs proceeds in a "lock-and-key" fashion, with the binding affinity dependent on structural differences among the sialylated compounds examined. (ii) The binding of the leg and the sialylated oligosaccharide is cooperative, with Hill constants ranging from 2 to 3. (iii) Mycoplasma legs may generate a drag force after a stroke, because the gliding speed decreased and pivoting motion occurred more frequently when the number of working legs was reduced by the addition of free sialylated compounds.

    DOI: 10.1128/JB.01141-12

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Misc.

  • Gliding Machinery of <i>Mycoplasma mobile</i> Visualized by High-speed AFM Peer-reviewed

    Kobayashi Kohei, Kodera Noriyuki, Tahara Yuhei O, Toyonaga Takuma, Kasai Taishi, Ando Toshio, Miyata Makoto

    KENBIKYO54 ( 2 ) 67 - 71   30 8 2019

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    Language:Japanese   Publisher:The Japanese Society of Microscopy  

    <i>Mycoplasma mobile</i>, a fish pathogenic bacterium lacking a peptidoglycan layer glides on a host cell surface with a unique mechanism. In the gliding mechanism, the force is generated through ATP hydrolysis on a gliding motor, evolved from F-type ATPase. We visualized the structural changes of gliding motors in living cells by using high-speed atomic force microscopy (high-speed AFM) which is a unique method to directly observe the dynamic molecules. The high-speed AFM visualized particle structures forming chains at intervals about 30 nm in the cell, consistent with the gliding motor observed by electron microscopy. Half of particles showed 8 nm shift to the left side relative to the gliding direction of cell and 5 nm sink to the cytoplasm side. The others stayed static through the observation. The frequency of the movement was reduced by sodium azide, F-type ATPase inhibitor, suggesting that the movement depends on ATP hydrolysis. In the gliding mechanism, the movement should be converted and amplified to the step of “leg” through “crank”, respectively composed of Gli349 and Gli521 on cell surface.

    DOI: 10.11410/kenbikyo.54.2_67

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    Other Link: https://ndlsearch.ndl.go.jp/books/R000000004-I030011194

  • バクテリアべん毛モーターの回転を測る—特集 運動マシナリーの多様性から見えるもの(前編)

    曽和 義幸, 笠井 大司

    生物工学会誌 / 日本生物工学会 編96 ( 4 ) 183 - 186   2018

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    Language:Japanese   Publisher:吹田 : 日本生物工学会  

    コレクション : 国立国会図書館デジタルコレクション > 電子書籍・電子雑誌 > 学術機関 > 学協会

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    Other Link: https://ndlsearch.ndl.go.jp/books/R000000004-I029033505

Presentations

  • The analysis of Spiroplasma eriocheiris cell division proteins

    Taishi Kasai, Yuhei O. Tahara, Makoto Miyata, Daisuke Shiomi

    Congress of International Organization for Mycoplasmology 

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    Event date: 16 7 2023 - 20 7 2023

    Language:English   Presentation type:Poster presentation  

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  • Measurement of the stall torque generated by the bacterial flagellar motor

    Taishi Kasai, Yoshiyuki Sowa

    International Union of Pure and Applied Biophysics Congress 

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    Event date: 16 7 2017 - 20 7 2017

    Language:English   Presentation type:Poster presentation  

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  • 単一糖鎖アレイを用いたマイコプラズマ・ モービレの滑走の詳細解析

    笠井大司, 浜田 祐, 宮田真人

    日本マイコプラズマ学会 

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    Event date: 22 5 2015 - 23 5 2015

    Presentation type:Oral presentation (general)  

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  • 単一のシアル酸オリゴ糖上でのマイコプラズマの結合と滑走

    笠井大司, 浜田 祐, 宮田真人

    日本マイコプラズマ学会 

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    Event date: 22 5 2014 - 23 5 2014

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  • 単一のシアル酸オリゴ糖上におけるマイコプラズマ滑走運動

    笠井大司, 浜田 祐, 宮田真人

    日本マイコプラズマ学会 

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    Event date: 23 5 2013 - 24 5 2013

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  • Catch of sialylated oligosaccharide by Mycoplasma mobile and Mycoplasma pneumoniae in gliding

    Taishi Kasai, Daisuke Nakane, Hideharu Ishida, Hiromune Ando, Makoto Kiso, Makoto Miyata

    Congress of International Organization for Mycoplasmology 

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    Event date: 15 7 2012 - 20 7 2012

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  • 遊離のシアル酸オリゴ糖によるマイコプラズマの滑走阻害から示唆される”あし”の動き

    笠井大司, 中根大介, 石田秀治, 安藤弘宗, 木曽 真, 宮田真人

    日本マイコプラズマ学会 

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    Event date: 24 5 2012 - 25 5 2012

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  • Sialylated oligosaccharide recognized by legs in Mycoplasma

    Taishi Kasai, Daisuke Nakane, Hideharu Ishida, Hiromune Ando, Makoto Kiso, Makoto Miyata

    Gordon Research Conference Sensory Transduction in Microorganisms 

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    Event date: 15 1 2012 - 20 1 2012

    Language:English   Presentation type:Poster presentation  

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  • Sialylated oligosaccharide recognized by Mycoplasma mobile and Mycoplasma pneumoniae leg proteins

    Taishi Kasai, Daisuke Nakane, Hideharu Ishida, Hiromune Ando, Makoto Kiso, Makoto Miyata

    Congress of Asian Organization for Mycoplasmology 

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    Event date: 19 10 2011 - 21 10 2011

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  • Sialylated oligosaccharide recognized by Mycoplasma mobile and Mycoplasma pneumoniae leg proteins involved in gliding motility

    Taishi Kasai, Daisuke Nakane, Hideharu Ishida, Hiromune Ando, Makoto Kiso, Makoto Miyata

    International Union of Microbiological Societies Congress 

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    Event date: 6 9 2011 - 9 9 2011

    Language:English   Presentation type:Poster presentation  

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  • Structure of silalyl oligosaccharide recognized by Mycoplasma leg proteins

    Taishi Kasai, Daisuke Nakane, Hideharu Ishida, Hiromune Ando, Makoto Kiso, Makoto Miyata

    Congress of International Organization for Mycoplasmology 

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    Event date: 11 7 2010 - 16 7 2010

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  • マイコプラズマのあしが認識するシアル酸オリゴ糖の構造

    笠井大司, 中根大介, 石田秀治, 安藤弘宗, 木曽 真, 宮田真人

    日本マイコプラズマ学会 

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    Event date: 10 6 2010 - 11 6 2010

    Language:Japanese   Presentation type:Oral presentation (general)  

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