Chemical cage crystallization encapsulating membrane proteins

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06505
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 43020:Structural biochemistry-related
• Research Institution: Kyoto University
• Principal Investigator: Nakura Yoshiko (中田) 京都大学, 高等研究院, 特定助教 (70799220)
• Co-Investigator(Kenkyū-buntansha): 藤川 鷹王 京都大学, 高等研究院, 研究員 (70839688)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 膜タンパク質 / 化学ケージ / 分子自己集合 / 構造解析 / 固定化タグ

Outline of Final Research Achievements

In this study, we worked on problems solving as bellow to establish an innovative methodology: chemical cage crystallization method that encapsulates membrane proteins by making full use of “self-assembly".
(1) Chemical cages are synthesized in organic solvents and are stable in that environment, but they must be modified to be stable in the same environment as membrane proteins. We designed and modified a cage stable in aqueous solution and its reaction.
(2) To determine the structure of membrane proteins encapsulated in the cage, it is necessary to make the position of the membrane protein with respect to the cage uniform. We designed and several tags and linkers in a fixed position on the cage without fluctuation. We immobilized the membrane proteins to the DNA origami plates to evaluate protein fluctuation.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

細胞内外の情報受容伝達、物質の取込みや不要物の排出、エネルギー生産など生命維持に必須な活動に膜タンパク質が果たす役割は多岐に渡り、多くの疾患にも関わっている。しかし、繊細で個性豊かな膜タンパク質の結晶構造解析は難しく、未だ多くの構造未解明な標的があり、既存のアプローチとは異なる革新的な方法論が必要である。化学ケージ結晶化法の利点を活かした方法論が確立できれば、膜タンパク質のX線結晶構造解析が飛躍的に進む。革新的方法論を確立するにあたり、本研究がその礎となり構造機能生物学に大きな貢献をもたらす。