Structural analysis and protein engineering for clarifying the molecular mechanism of the taste-modifying activity of neoculin

2010 Fiscal Year Final Research Report

• Project/Area Number: 21880015
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Food science
• Research Institution: The University of Tokyo
• Principal Investigator: NAKAJIMA Kenichiro The University of Tokyo, 大学院・農学生命科学研究科, 特任助教 (70554492)
• Project Period (FY): 2009 – 2010
• Keywords: 味覚修飾活性 / ヒスチジン / NMR

Research Abstract

Neoculin is a sweet protein with taste-modifying activity converting sourness into sweetness. In this study, I performed a mutational analysis of neoculin to identify the important residue(s) for this pH-dependent activity. It revealed that one histidine residue in neoculin was critical for the activity. NMR analysis also performed to evaluate the structural-activity relationship of neoculin. It was found that the neoculin structurally changed between neutral and acidic pH.

Research Products

• [Journal Article] Identification and Modulation of the Key Amino Acid Residue Responsible for the pH Sensitivity of Neoculin, a Taste-modifying Protein (2011)
  • Author(s): Ken-ichiro Nakajima, Kanako Yokoyama, Taichi Koizumi, Ayako Koizumi, Tomiko Asakura, Tohru Terada, Katsuyoshi Masuda, Keisuke Ito, Akiko Shimizu-Ibuka, Takumi Misaka, Keiko Abe
  • Journal Title: PLoS One under review
  • Peer Reviewed
• [Journal Article] Non-acidic Compounds Induce the Intense Sweet Taste of Neoculin, a Taste-modifying Protein (2011)
  • Author(s): Ken-ichiro Nakajima, Ayako Koizumi, Kisho Iizuka, Keisuke Ito, Yuji Morita, Taichi Koizumi, Tomiko Asakura, Akiko Shimizu-Ibuka, Takumi Misaka, Keiko Abe
  • Journal Title: Biosci.Biotechnol.Biochem. under review
  • Peer Reviewed
• [Presentation] NMRによる味覚修飾タンパク質ネオクリンの構造変化の解析 (2011)
  • Author(s): 小泉太一、寺田透、中島健一朗、古泉文子、土屋麻美、朝倉富子、阿部啓子、三坂巧
  • Organizer: 日本農芸化学会
  • Place of Presentation: 京都
  • Year and Date: 2011-03-26
• [Presentation] 点変異導入による味覚修飾タンパク質ネオクリンの活性制御 (2011)
  • Author(s): 金田康平、中島健一朗、小泉太一、古泉文子、土屋麻美、朝倉富子、阿部啓子、三坂巧
  • Organizer: 日本農芸化学会
  • Place of Presentation: 京都
  • Year and Date: 2011-03-26
• [Presentation] 味覚修飾タンパク質ネオクリンの構造、機能相関の分光学的解析 (2010)
  • Author(s): 小泉太一、森田悠治、中島健一朗、飯塚希翔、古泉文子、清水(井深)章子、朝倉富子、三坂巧、阿部啓子
  • Organizer: 日本農芸化学会
  • Place of Presentation: 東京
  • Year and Date: 2010-03-28
• [Presentation] 味覚修飾タンパク質ネオクリンとそのバリアントの培養細胞を用いた活性評価 (2010)
  • Author(s): 中島健一朗、横山可那子、清水(井深)章子、小泉太一、古泉文子、朝倉富子、村清司、徳江千代子、荒井綜一、三坂巧、阿部啓子
  • Organizer: 日本農芸化学会
  • Place of Presentation: 東京
  • Year and Date: 2010-03-28