Patents by Inventor Kappei Tsukahara

Kappei Tsukahara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8323917
    Abstract: The present invention enables screening for compounds that inhibit the transport of GPI-anchored proteins to fungal cell walls, using a simple assay for transacylation to GlcN-PI using membrane fraction expressing GWT1 protein. New antifungal agents can be created that inhibit the synthesis of fungal cell walls and also inhibit adhesion to host cells by inhibiting the transport of GPI-anchored proteins to fungal cell walls.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: December 4, 2012
    Assignees: National Institute of Advanced Industrial Science and Technology, Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Mamiko Tsuchiya, Yoshifumi Jigami, Kenichi Nakayama, Mariko Umemura, Michiyo Okamoto
  • Patent number: 8252294
    Abstract: The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite P. falciparum. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.
    Type: Grant
    Filed: March 4, 2011
    Date of Patent: August 28, 2012
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Katsura Hata, Kaoru Ogawa, Itaru Tsukada, Kazutaka Nakamoto, Koji Sagane, Keigo Tanaka, Kappei Tsukahara, Toshihiro Horii
  • Publication number: 20110201816
    Abstract: The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite P. falciparum. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.
    Type: Application
    Filed: March 4, 2011
    Publication date: August 18, 2011
    Applicant: EISAI R&D MANAGEMENT CO., LTD
    Inventors: Katsura Hata, Kaoru Ogawa, Itaru Tsukada, Kazutaka Nakamoto, Koji Sagane, Keigo Tanaka, Kappei Tsukahara, Toshihiro Horii
  • Patent number: 7999090
    Abstract: The present invention provides isolated DNA encoding a GWT1 protein having activity to confer resistance of a fungus against a compound of formula Ia, and wherein a defect of a function of the GWT1 protein leads to a decrease in the amount of a glycosylphosphatidylinositol (GPI)-anchored protein in the cell wall of a fungus.
    Type: Grant
    Filed: April 15, 2008
    Date of Patent: August 16, 2011
    Assignee: Eisai Co., Ltd
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7928215
    Abstract: The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite P. falciparum. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: April 19, 2011
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Katsura Hata, Kaoru Ogawa, Itaru Tsukada, Kazutaka Nakamoto, Koji Sagane, Keigo Tanaka, Kappei Tsukahara, Toshihiro Horii
  • Patent number: 7928209
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: April 19, 2011
    Assignee: Eisai R & D Management Co. Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7910712
    Abstract: The present invention provides isolated DNA encoding a GWT1 protein having activity to confer resistance of a fungus against a compound of formula Ia, and wherein a defect of a function of the GWT1 protein leads to a decrease in the amount of a glycosylphosphatidylinositol (GPI)-anchored protein in the cell wall of a fungus.
    Type: Grant
    Filed: April 15, 2008
    Date of Patent: March 22, 2011
    Assignee: Eisai R&D Management Co., Ltd
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7897387
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: March 1, 2011
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20100240074
    Abstract: Provided is a set of yeast gene knockout strains whose drug sensitivity is significantly improved. A set of yeast cells of the invention is a set of yeast cells comprising two or more types of yeast cells, wherein at least one mutually different gene has been deleted or mutated in each of the two or more types of yeast cells, and all of the two or more types of yeast cells are drug hypersensitive yeast cells in which the expression of at least one drug sensitivity-related gene is regulated.
    Type: Application
    Filed: June 16, 2008
    Publication date: September 23, 2010
    Applicant: EISAI R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Kaoru Mitsuhashi, Makiyo Iida
  • Publication number: 20090325228
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 15, 2008
    Publication date: December 31, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Oba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7541332
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: June 2, 2009
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20090117586
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 1, 2008
    Publication date: May 7, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD.
    Inventors: KAPPEI TSUKAHARA, KATSURA HATA, KOJI SAGANE, KAZUTAKA NAKAMOTO, MAMIKO TSUCHIYA, NAOAKI WATANABE, FUMINORI OHBA, ITARU TSUKADA, NORIHIRO UEDA, KEIGO TANAKA, JUNKO KAI
  • Publication number: 20090098636
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 15, 2008
    Publication date: April 16, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20090011951
    Abstract: An expression of an ergosterol biosynthetic enzyme such as ERG6 and ERG3 is regulated with an inducible promoter, and transformation is performed in a state where the enzyme is expressed, and then screening or assay of drug-resistant colonies is performed in a state where the expression of the enzyme is repressed.
    Type: Application
    Filed: October 28, 2005
    Publication date: January 8, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD.
    Inventors: Kaoru Mitsuhashi, Kappei Tsukahara
  • Publication number: 20080261272
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 15, 2008
    Publication date: October 23, 2008
    Applicant: EISAI R&D MANAGEMENT CO., LTD
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20080166765
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: December 17, 2007
    Publication date: July 10, 2008
    Applicant: Eisai R&D Management, Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Oba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7375204
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: May 20, 2008
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20060240429
    Abstract: The present invention enables screening for compounds that inhibit the transport of GPI-anchored proteins to fungal cell walls, using a simple assay for transacylation to GlcN-PI using membrane fraction expressing GWT1 protein. New antifungal agents can be created that inhibit the synthesis of fungal cell walls and also inhibit adhesion to host cells by inhibiting the transport of GPI-anchored proteins to fungal cell walls.
    Type: Application
    Filed: November 21, 2003
    Publication date: October 26, 2006
    Inventors: Kappei Tsukahara, Mamiko Tsuchiya, Yoshifumi Jigami, Kenichi Nakayama, Mariko Umemura, Michiyo Okamoto
  • Publication number: 20060234283
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 19, 2006
    Applicant: Eisai Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20060234349
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 19, 2006
    Applicant: Eisai Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai