Patents by Inventor Atsushi Ichiyanagi

Atsushi Ichiyanagi 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: 10767211
    Abstract: This invention provides an amadoriase having high reactivity with ?-fructosyl hexapeptide (?F6P) derived from the ?-chain amino terminus of glycated hemoglobin (HbAlc), which enables satisfactory quantification of ?F6P cleaved from HbAlc. A novel amadoriase is derived from the amadoriase of the genus Coniochaeta by substitution of one or more amino acids at positions selected from the group consisting of positions 62, 63, 102, 106, 110, 113, 355, and 419. Such amadoriase enables rapid, simple, accurate, and satisfactory quantification of ?F6P cleaved from HbAlc. With the use of such amadoriase, a method for measurement of HbAlc by an enzymatic method and a kit for measurement of HbAlc that are based on the same principle as used in the conventional standard method and excellent in terms of the relevance with the standard method.
    Type: Grant
    Filed: April 26, 2013
    Date of Patent: September 8, 2020
    Assignee: Kikkoman Corporation
    Inventors: Atsushi Ichiyanagi, Yosuke Masakari
  • Publication number: 20200263228
    Abstract: Provided is a composition by which glycated hemoglobin can be measured even in the presence of a stronger surfactant than a conventional case. Also provided is a buffer and/or stabilizer which maintains the residual activity of an amadoriase or lowers a reduction of residual activity. The present invention provides a composition for use in measuring glycated hemoglobin containing an amadoriase having substitution of one or more amino acid residues at a position(s) corresponding to an amino acid(s) selected from the group consisting of position 262, position 257, position 249, position 253, position 337, position 340, position 232, position 129, position 132, position 133, position 44, position 256, position 231 and position 81 of an amadoriase derived from the genus Coniochaeta and represented by SEQ ID No: 1 or 3, and having residual activity even in the presence of a surfactant.
    Type: Application
    Filed: March 27, 2020
    Publication date: August 20, 2020
    Applicant: Kikkoman Corporation
    Inventors: Yosuke MASAKARI, Atsushi ICHIYANAGI
  • Patent number: 10697979
    Abstract: This invention provides an amadoriase that can react with a wide variety of glycated peptides generated upon hydrolysis of the ? chain of hemoglobin A1c (HbA1c) to generate hydrogen peroxide, a method for measurement of HbA1c using such amadoriase, and a reagent kit for measurement of HbA1c using such amadoriase. Provided is an amadoriase obtained by substitution of one or more amino acids at positions corresponding to amino acids selected from the group consisting of amino acids 62, 63, 102, 106, 110, 113, and 355 in the amino acid sequence of the amadoriase derived from the genus Coniochaeta or the like which amadoriase is capable of oxidizing a wide variety of glycated peptides to generate hydrogen peroxide. Further provided is a method for measurement of HbA1c comprising using such amadoriase as well as a reagent kit for measurement of HbA1c comprising such amadoriase.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: June 30, 2020
    Assignee: Kikkoman Corporation
    Inventor: Atsushi Ichiyanagi
  • Patent number: 10619183
    Abstract: Provided is a composition by which glycated hemoglobin can be measured even in the presence of a stronger surfactant than a conventional case. Also provided is a buffer and/or stabilizer which maintains the residual activity of an amadoriase or lowers a reduction of residual activity. The present invention provides a composition for use in measuring glycated hemoglobin containing an amadoriase having substitution of one or more amino acid residues at a position(s) corresponding to an amino acid(s) selected from the group consisting of position 262, position 257, position 249, position 253, position 337, position 340, position 232, position 129, position 132, position 133, position 44, position 256, position 231 and position 81 of an amadoriase derived from the genus Coniochaeta and represented by SEQ ID No: 1 or 3, and having residual activity even in the presence of a surfactant.
    Type: Grant
    Filed: August 8, 2014
    Date of Patent: April 14, 2020
    Assignee: Kikkoman Corporation
    Inventors: Yosuke Masakari, Atsushi Ichiyanagi
  • Publication number: 20190316174
    Abstract: Provided is a compound which accelerates the enzymatic reaction catalyzed by an oxidase. The present invention provides an oxidase reaction accelerating agent comprising a compound represented by formula (I) and a method using the same.
    Type: Application
    Filed: July 13, 2017
    Publication date: October 17, 2019
    Applicant: Kikkoman Corporation
    Inventors: Atsushi Ichiyanagi, Kazuhiko SHIMOJI
  • Publication number: 20190300929
    Abstract: Provided is a compound capable of accelerating the enzymatic reaction catalyzed by peroxidase. The present invention provides a peroxidase reaction accelerating agent comprising a compound represented by formula (I) and a method for measuring hydrogen peroxide using the same.
    Type: Application
    Filed: July 13, 2017
    Publication date: October 3, 2019
    Applicant: Kikkoman Corporation
    Inventors: Atsushi ICHIYANAGI, Kazuhiko SHIMOJI
  • Publication number: 20190119715
    Abstract: This invention provides an HbA1c dehydrogenase that is capable of directly acting on hemoglobin A1c and is less likely to be influenced by oxygen concentration and a method for measurement and a kit of assay reagents using such HbA1c dehydrogenase. The HbA1c dehydrogenase having dehydrogenase activity and capable of directly acting on HbA1c is obtained by substitution of one or more amino acid residues at positions corresponding to positions 280, 269, 54, 241, and 267 of the amadoriase that is capable of directly acting on hemoglobin A1c and is derived from, for example, the genus Coniochaeta. This invention also provides a method for measurement of HbA1c, a kit of assay reagents, and a sensor using such HbA1c dehydrogenase. Such HbA1c dehydrogenase is capable of directly acting on hemoglobin A1c and has lowered oxidase activity and/or enhanced dehydrogenase activity.
    Type: Application
    Filed: April 21, 2017
    Publication date: April 25, 2019
    Applicant: Kikkoman Corporation
    Inventors: Atsushi Ichiyanagi, Yosuke MASAKARI
  • Publication number: 20180371429
    Abstract: This invention provides an amadoriase having improved specific activity on a glycated substrate, compared with conventional amadoriase. Provided is an amadoriase comprising a substitution of the amino acid at the position corresponding to position 64 of the amino acid sequence as shown in SEQ ID NO: 1 with an amino acid selected from the group consisting of glycine, serine, methionine, leucine, threonine, valine, and isoleucine, a method for measurement of HbA1c, and a reagent kit for measurement of HbA1c using such amadoriase. Such method and kit for measurement enable rapid, simple, and accurate quantification of HbA1c.
    Type: Application
    Filed: April 4, 2016
    Publication date: December 27, 2018
    Applicant: Kikkoman Corporation
    Inventors: Atsushi ICHIYANAGI, Airi KOMATSUZAKI
  • Publication number: 20170355967
    Abstract: Provided are an amadoriase that is less likely to be influenced by oxygen concentration and a method and a reagent kit for measurement of HbA1c using such amadoriase. Provided are an amadoriase that is obtained via substitution of one or more amino acid residues at a position or positions corresponding to the position(s) selected from the group consisting of positions 280, 267, 269, 54, and 241 of the amadoriase derived from the genus Coniochaeta, a method for measurement of HbA1c, a reagent kit for measurement, and a sensor using such amadoriase. The modified amadoriase according to the invention has a lowered oxidase activity and an enhanced dehydrogenase activity, and this enables the use of an electron mediator, and this reduces the influence of oxygen concentration. Thus, HbA1c can be measured with high sensitivity.
    Type: Application
    Filed: October 23, 2015
    Publication date: December 14, 2017
    Applicant: Kikkoman Corporation
    Inventors: Yosuke Masakari, Airi KOMATSUZAKI, Atsushi ICHIYANAGI
  • Patent number: 9708586
    Abstract: This invention provides an amadoriase having high substrate specificity to fructosyl valyl histidine. Such amadoriase comprises substitution of one or more amino acid residues at positions corresponding to amino acids selected from the group consisting of position 98, position 259, position 154, position 125, position 261, position 263, position 106, position 103, position 355, position 96, position 66, position 67, position 70, position 100, position 110, position 113, position 114, and position 156 in the amadoriase derived from the genus Coniochaeta. This invention enables accurate measurement of ?-fructosyl valyl histidine derived from the ?-chain amino terminus in glycated hemoglobin in the presence of ?-fructosyl lysine.
    Type: Grant
    Filed: May 19, 2015
    Date of Patent: July 18, 2017
    Assignee: Kikkoman Corporation
    Inventors: Atsushi Ichiyanagi, Kozo Hirokawa, Yasuko Tanabe, Yosuke Masakari
  • Patent number: 9701949
    Abstract: An amadoriase having a substitution or a deletion of one or more amino acid residues at positions corresponding to amino acids selected from the group consisting of three amino acid residues from the carboxyl terminal and amino acids at positions 151, 43, 53, 267, 350, 185, 196, 299 and 323 in the amino acid sequence of amadoriase derived from the Coniochaeta species indicated in SEQ ID NO: 1. The amadoriase having a heat resistance which is superior to that of a conventional amadoriase.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: July 11, 2017
    Assignee: KIKKOMAN CORPORATION
    Inventors: Yosuke Masakari, Atsushi Ichiyanagi
  • Patent number: 9493814
    Abstract: A flavin-binding glucose dehydrogenase having high substrate specificity for D-glucose and decreased reactivity to D-xylose and/or maltose. More specifically, a flavin-binding glucose dehydrogenase having one or more amino acid substitutions at a position corresponding to position 78, position 79, position 81, position 121, position 122, position 123, position 569 and position 612 of Mucor-derived flavin-binding glucose dehydrogenase. The flavin-binding glucose dehydrogenase enables D-glucose to be measured accurately without being susceptible to the effects of the presence of D-xylose and/or maltose, even under conditions of mounting a large amount of an enzyme such as in glucose sensors.
    Type: Grant
    Filed: November 1, 2012
    Date of Patent: November 15, 2016
    Assignee: KIKKOMAN CORPORATION
    Inventors: Yasuko Araki, Atsushi Ichiyanagi, Keiichi Ichikawa, Kozo Hirokawa
  • Patent number: 9469844
    Abstract: A heat-resistant flavin-bound glucose dehydrogenase having a high substrate specificity for D-glucose, an method for producing the same, and a transformant used for the same. A flavin-bound glucose dehydrogenase gene encoding a flavin-bound glucose dehydrogenase derived from Mucor is introduced into yeast, Zygosaccharomyces, to obtain a transformant. Subsequently, the yeast transformant is cultured to obtain a flavin-bound glucose dehydrogenase from the culture. The heat-resistant flavin-bound glucose dehydrogenase is less susceptible to the effects of dissolved oxygen and allows accurate measurement of glucose even in the presence of sugar compounds other than glucose in a sample.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: October 18, 2016
    Assignee: KIKKOMAN CORPORATION
    Inventors: Ryoko Tajima, Atsushi Ichiyanagi, Kozo Hirokawa, Masanobu Yuzuki
  • Publication number: 20160274129
    Abstract: This invention provides an amadoriase that can react with a wide variety of glycated peptides generated upon hydrolysis of the ? chain of hemoglobin Alc (HbAlc) to generate hydrogen peroxide, a method for measurement of HbAlc using such amadoriase, and a reagent kit for measurement of HbAlc using such amadoriase. Provided is an amadoriase obtained by substitution of one or more amino acids at positions corresponding to amino acids selected from the group consisting of amino acids 62, 63, 102, 106, 110, 113, and 355 in the amino acid sequence of the amadoriase derived from the genus Coniochaeta or the like which amadoriase is capable of oxidizing a wide variety of glycated peptides to generate hydrogen peroxide. Further provided is a method for measurement of HbAlc comprising using such amadoriase as well as a reagent kit for measurement of HbAlc comprising such amadoriase.
    Type: Application
    Filed: October 24, 2014
    Publication date: September 22, 2016
    Applicant: Kikkoman Corporation
    Inventor: Atsushi ICHIYANAGI
  • Publication number: 20160251695
    Abstract: This invention provides an amadoriase that acts on the ?-chain of hemoglobin A1c (HbA1c) and generates hydrogen peroxide, a method for measurement of HbA1c using such amadoriase, and a reagent kit for measurement of HbA1c using such amadoriase. The method for measurement of HbA1c involves the use of an amadoriase that has specific activity of 0.1 U/mg or greater to ?F6P and oxidizes the HbA1c ?-chain amino terminus so as to generate hydrogen peroxide, and the reagent kit for measurement of HbA1c comprises such amadoriase. The method and the kit for measurement of HbA1c enable quantification of HbA1c to be performed rapidly, simply, and accurately.
    Type: Application
    Filed: October 24, 2014
    Publication date: September 1, 2016
    Applicant: Kikkoman Corporation
    Inventors: Yosuke MASAKARI, Atsushi ICHIYANAGI
  • Publication number: 20160186232
    Abstract: Provided is a composition by which glycated hemoglobin can be measured even in the presence of a stronger surfactant than a conventional case. Also provided is a buffer and/or stabilizer which maintains the residual activity of an amadoriase or lowers a reduction of residual activity. The present invention provides a composition for use in measuring glycated hemoglobin containing an amadoriase having substitution of one or more amino acid residues at a position(s) corresponding to an amino acid(s) selected from the group consisting of position 262, position 257, position 249, position 253, position 337, position 340, position 232, position 129, position 132, position 133, position 44, position 256, position 231 and position 81 of an amadoriase derived from the genus Coniochaeta and represented by SEQ ID No: 1 or 3, and having residual activity even in the presence of a surfactant.
    Type: Application
    Filed: August 8, 2014
    Publication date: June 30, 2016
    Applicant: Kikkoman Corporation
    Inventors: Yosuke MASAKARI, Atsushi ICHIYANAGI
  • Patent number: 9238802
    Abstract: A flavin-bound glucose dehydrogenase (FAD-GDH) with high substrate specificity for D-glucose. A gene encoding a mutant FAD-GDH with its N-terminal region, containing an amino acid sequence corresponding to MKITAAIITVATAFASFASA that exists in the N-terminal region, deleted from the amino acid sequence of a wild-type FAD-GDH derived from Mucor is introduced into E. coli to obtain an E. coli transformant. Subsequently, this E. coli transformant is cultured to obtain an FAD-GDH with a specific N-terminal region deleted. The transformant allows the production of a large amount of GDH in a short time as compared with the original microorganism. An FAD-GDH that is less susceptible to the effects of dissolved oxygen and allows accurate measurement of glucose even in the presence of sugar compounds other than glucose in a sample.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: January 19, 2016
    Assignee: KIKKOMAN CORPORATION
    Inventors: Ryoko Tajima, Atsushi Ichiyanagi, Eriko Yoshihara, Kozo Hirokawa
  • Publication number: 20150247129
    Abstract: This invention provides an amadoriase having high substrate specificity to fructosyl valyl histidine. Such amadoriase comprises substitution of one or more amino acid residues at positions corresponding to amino acids selected from the group consisting of position 98, position 259, position 154, position 125, position 261, position 263, position 106, position 103, position 355, position 96, position 66, position 67, position 70, position 100, position 110, position 113, position 114, and position 156 in the amadoriase derived from the genus Coniochaeta. This invention enables accurate measurement of ?-fructosyl valyl histidine derived from the ?-chain amino terminus in glycated hemoglobin in the presence of ?-fructosyl lysine.
    Type: Application
    Filed: May 19, 2015
    Publication date: September 3, 2015
    Applicant: Kikkoman Corporation
    Inventors: Atsushi Ichiyanagi, Kozo Hirokawa, Yasuko Tanabe, Yosuke Masakari
  • Patent number: 9062286
    Abstract: This invention provides an amadoriase having high substrate specificity to fructosyl valyl histidine. Such amadoriase comprises substitution of one or more amino acid residues at positions corresponding to amino acids selected from the group consisting of position 98, position 259, position 154, position 125, position 261, position 263, position 106, position 103, position 355, position 96, position 66, position 67, position 70, position 100, position 110, position 113, position 114, and position 156 in the amadoriase derived from the genus Coniochaeta. This invention enables accurate measurement of ?-fructosyl valyl histidine derived from the ?-chain amino terminus in glycated hemoglobin in the presence of ?-fructosyl lysine.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: June 23, 2015
    Assignee: Kikkoman Corporation
    Inventors: Atsushi Ichiyanagi, Kozo Hirokawa, Yasuko Tanabe, Yosuke Masakari
  • Publication number: 20150118700
    Abstract: This invention provides an amadoriase having high reactivity with ?-fructosyl hexapeptide (?F6P) derived from the ?-chain amino terminus of glycated hemoglobin (HbAlc), which enables satisfactory quantification of ?F6P cleaved from HbAlc. A novel amadoriase is derived from the amadoriase of the genus Coniochaeta by substitution of one or more amino acids at positions selected from the group consisting of positions 62, 63, 102, 106, 110, 113, 355, and 419. Such amadoriase enables rapid, simple, accurate, and satisfactory quantification of ?F6P cleaved from HbAlc. With the use of such amadoriase, a method for measurement of HbAlc by an enzymatic method and a kit for measurement of HbAlc that are based on the same principle as used in the conventional standard method and excellent in terms of the relevance with the standard method.
    Type: Application
    Filed: April 26, 2013
    Publication date: April 30, 2015
    Inventors: Atsushi Ichiyanagi, Yosuke Masakari