Novel mechanism of starch-granule degradation and its application

• Project/Area Number: 26660079
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied biochemistry
• Research Institution: Hokkaido University
• Principal Investigator: KIMURA Atsuo 北海道大学, (連合)農学研究科(研究院), 教授 (90186312)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 植物 / デンプン粒分解 / 長鎖基質認識酵素 / 澱粉粒分解 / 酵素

Outline of Final Research Achievements

This project aims at the formation of theory that plant α-glucosidase is the key-enzyme to degrade starch granules by elucidating its molecular mechanism. The following results were obtained. (1) Plant enzymes display the starch granule-binding and -hydrolyzing abilities, implying that key-enzyme is an α-glucosidase. (2) We clarify the long substrate recognition mechanism of sugar beet α-glucosidase by the analysis using its three-dimensional structure and long substrate-mimic inhibitors. (3) We also reveal the structural factor of rice enzyme to bind and hydrolyze starch granules. (4) It is found that plant β-amylase and α-glucosidase synergistically degrade starch granules.

Research Products

• [Journal Article] 長鎖阻害剤の利用による植物α-グルコシダーゼの機能構造相関の解明 (2016)
  • Author(s): 田上貴祥, 山下恵太郎, 奥山正幸, 森 春英, 姚 閔, 木村淳夫
  • Journal Title: 応用糖質科学 Volume: 印刷中
  • Peer Reviewed / Open Access
• [Journal Article] α-Glucosidases and α-1,4-glucan lyases: structures, functions, and physiological actions (2016)
  • Author(s): Masayuki Okuyama, Wataru Saburi, Haruhide Mori, and Atsuo Kimura
  • Journal Title: Cellular and Molecular Life Sciences Volume: 印刷中
  • Peer Reviewed / Open Access
• [Journal Article] Structural advantage of sugar beet α-glucosidase to stabilize the Michaelis complex with long-chain substrate (2015)
  • Author(s): Tagami T, Yamashita K, Okuyama M, Mori H, Yao M, Kimura A
  • Journal Title: J. Biol. Chem. Volume: 290 Issue: 3 Pages: 1796-1803
  • DOI: 10.1074/jbc.m114.606939
  • Peer Reviewed
• [Presentation] 長鎖阻害剤の利用による植物α-グルコシダーゼの機能構造相関の解明 (2015)
  • Author(s): 田上貴祥、山下恵太郎、奥山正幸、森春英、姚閔、木村淳夫
  • Organizer: 応用糖質科学シンポジウム
  • Place of Presentation: 東大寺総合文化センター（奈良県奈良市）
  • Year and Date: 2015-09-18
• [Presentation] Structural and biochemical studies of sugar beet α-glucosidase exhibiting high specificity for long-chain substrates. (2015)
  • Author(s): Takayoshi Tagami, Keitaro Yamashita, Masayuki Okuyama, Haruhide Mori, Min Yao, Atsuo Kimura
  • Organizer: 11th Carbohydrate Bioengineering Meeting
  • Place of Presentation: Otaniemi (Finland)
  • Year and Date: 2015-05-10
  • Int'l Joint Research
• [Presentation] テンサイα-グルコシダーゼの高重合度基質特異性はらせん構造の長鎖基質に適したサブサイト構造に起因する (2015)
  • Author(s): 田上貴祥, 山下恵太郎, 奥山正幸, 森 春英, 姚 閔, 木村淳夫
  • Organizer: 日本農芸化学会2015年度大会
  • Place of Presentation: 岡山大学（岡山県・岡山市）
  • Year and Date: 2015-03-26 – 2015-03-29
• [Book] Application of Microbiology and Biochemistry. in "Frontiers of Agricultural Science" (2015)
  • Author(s): Atsuo Kimura, Masayuki Okuyama
  • Total Pages: 277
  • Publisher: Shoukadoh Book Sellers
• [Remarks] 分子酵素学研究室
  • URL: http://www.agr.hokudai.ac.jp/rfoa/abs/abs2-3.html