Development of a method for molecular structure analysis of proteins and other chiral molecules by vacuum ultraviolet circular dichroism measurement in supercritical water conditions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05559
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34020:Analytical chemistry-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Tanaka Masahito 国立研究開発法人産業技術総合研究所, 計量標準総合センター, 研究グループ長 (30386643)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 分子構造 / 円二色性 / キラリティ / 光吸収 / 分光計測

Outline of Final Research Achievements

The objective of this study was to develop and evaluate the technologies required for circular dichroism measurement under high-pressure and high-temperature conditions (pressure above 22.1 MPa and temperature above 374 °C) such as supercritical water conditions.　First, an optical cell system for high-pressure and high-temperature conditions was developed by using a YAG ceramic window as an optical window. The cell was successfully tested at pressures of 40 MPa or higher and temperatures up to 400°C, exceeding the supercritical water conditions. We have also developed a spectroscopic system that can measure circular dichroism spectra in a relatively short time. Using the developed cell and others, we measured the circular dichroism spectra of standard samples and observed circular dichroism peaks with opposite signs for S- and R-isomers, and successfully measured circular dichroism with this system.

Free Research Field

分光分析、量子ビーム利用、キラル科学

Academic Significance and Societal Importance of the Research Achievements

本システムにおいて超臨界状態等の高温・高圧条件での分子構造変化の時間変化の測定が可能になる。近年、100 ℃を超えても活性を失わない超耐熱性タンパク質の発見や、高圧・高温水を用いたタンパク質の加水分解によるペプチドやアミノ酸の低コスト作製方法などが報告されており、本システムによって高圧・高温条件において、タンパク質等のキラルな分子・高分子の構造変化や反応を詳細に調査することができる。また他にも薬品等の滴下からの時間変化（ストップフロー測定）などにも応用できる。