Characterization of protein crystals based on the dislocation theory for the material application

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23579
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0401:Materials engineering, chemical engineering, and related fields
• Research Institution: Yokohama City University
• Principal Investigator: Suzuki Ryo 横浜市立大学, 理学部, 助教 (70846708)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: タンパク質結晶 / 力学的性質 / 転位 / X線回折 / インデンテーション / 圧縮試験

Outline of Final Research Achievements

We have conducted fundamental research on the mechanical properties of protein crystals for applications. In particular, we have conducted two main studies: (1) evaluation of the mechanical properties of protein crystals by macroscopic deformation tests, and (2) development of a method for observing crystal defects in protein crystals by synchrotron radiation X-ray topography, and precise evaluation of their perfection based on diffraction theory. In (1), Young's modulus and fracture stress were successfully estimated by deformation tests using huge crystals up to 5 mm in size. In (2), we succeeded in constructing a method (Median Image Method) to observe crystal defects such as dislocations even in crystals for which it is difficult to obtain defect images by image analysis of a series of several hundred diffraction images taken by digital topography using an X-ray CCD camera.

Free Research Field

結晶工学

Academic Significance and Societal Importance of the Research Achievements

学術的意義としては、脆く壊れやすいと定性的な認知で収まっていたタンパク質結晶の力学的性質をヤング率や破壊応力、ひずみ量などの値から定量的な評価まで落とし込めたことにある。また、その変形機構は転位の運動による塑性変形に支配されていることから、本研究で得られた知見を基にその変形の制御を行うことで、高強度化法に期待できる。さらには、海洋問題をはじめとして現在課題となっているプラスチックのような人工高分子の代替素材として、自然由来のタンパク質結晶の工学的な利用は持続可能な社会に重要である。