Optimization of a method estimating for small-angle X-ray scattering by using Bayesian inference.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K00396
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Life / Health / Medical informatics
• Research Institution: Kochi University
• Principal Investigator: SEKI Yasutaka 高知大学, 教育研究部医療学系医学教育部門, 教授 (30377220)
• Co-Investigator(Kenkyū-buntansha): 中村 成芳 宇部工業高等専門学校, 一般科, 准教授 (20623995)
• Research Collaborator: KAWATA Yasushi ; KEZUKA Yuichiro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 蛋白質構造 / 天然変性蛋白質 / SAXS / NMR

Outline of Final Research Achievements

We measured high accuracy small-angle X-ray scattering (SAXS) data of both apomyoglobin on an urea-denatured condition and α-synuclein to be an intrinsically disordered protein. And these high accuracy data can be used for developing a new program that estimates for the SAXS data from protein conformation. Furthermore, molecular dynamics simulations were performed with the unfolded conformation of apomyoglobin as the initial state and the SAXS profiles were estimated with high accuracy using the trajectory data of atomic coordinates of the water obtained through this simulation. It was confirmed that the estimated SAXS profiles are consistent with the measured one. Finally, a hydration structure was able to be modeled referring to the trajectory of the water and the hydration effect for the SAXS profile was elucidated.

Free Research Field

分子生物物理学

Academic Significance and Societal Importance of the Research Achievements

SAXSプロフィルと多次元核磁気共鳴（NMR）の残余双極子結合（RDC）に対する実験再現性を等価に扱い，極めて効率的に高い実験再現性をもつ構造集団を得ることが出来る新たな鎖状分子モデリング法を開発した。この方法を用いて，尿素変性及び酸変性状態アポミオグロビンとαシヌクレインの予測構造集団を生成した。これらの構造集団の統計的な特徴を比較し，それぞれの状態の違いを明らかにした。この科研費で開発した，一連の解鎖状態タンパク質の解析方法は，創薬など幅広い分野での利用が期待される。