Quantification of protein conformational entropy on helix-bundle formation

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660091
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied biochemistry
• Research Institution: Kyoto Prefectural University
• Principal Investigator: Masayuki Oda 京都府立大学, 生命環境科学研究科(系), 准教授 (20318231)
• Co-Investigator(Renkei-kenkyūsha): SEKIGUCHI Hiroshi 公益財団法人高輝度光科学研究センター, 利用研究促進部門, 研究員 (00401563)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 動的構造 / 蛋白質 / 構造エントロピー

Outline of Final Research Achievements

I designed a model protein whose structure is changed from random to helix-bundle upon its metal binding to His residues introduced into the hydrophobic core, using another designed protein reported previously as the template. I could successfully generate the protein by additional destabilized mutation into the template protein. The main purpose of this study is to quantify the conformational entropy, and to correlate the structural ensemble with the structural information obtained from single-molecule analysis. To achieve the purpose, I carried out NMR, isothermal titration calorimetry (ITC), and diffracted X-ray tracking (DXT) experiments. The NMR experiments showed that one of the designed proteins was changed from random to helix-bundle structure upon its metal binding. The ITC experiments could determine the binding thermodynamics, and the DXT experiments could detect the structural dynamics and their changes upon the metal-binding at single-molecule level.

Free Research Field

蛋白質科学