Ultrafast spectroscopy of single photoresponsive proteins under fluctuation

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18203
• Research Category: Grant-in-Aid for Challenging Research (Pioneering)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 32:Physical chemistry, functional solid state chemistry, and related fields
• Research Institution: Institute for Molecular Science
• Principal Investigator: Kuramochi Hikaru 分子科学研究所, 協奏分子システム研究センター, 准教授 (40709367)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 超高速分光 / 単一分子分光 / 光応答性タンパク質

Outline of Final Research Achievements

The project promoted the development of a new spectroscopic technique that combines the concepts of advanced linear and non-linear spectroscopy and single-molecule spectroscopy, which have been independently developed until now. A new methodology was developed to obtain excitation spectra of molecules in solution at room temperature with single-molecule detection sensitivity and to observe their spontaneous fluctuations by constructing an ultra-broadband ultrashort pulse light source with a high repetition rate. A technical basis for observing the ultrafast dynamics of photoresponsive proteins and their fluctuations at the single-molecule level was established.

Free Research Field

物理化学

Academic Significance and Societal Importance of the Research Achievements

従来の分光法では，一般的には大多数の分子の集団に対して測定が行われるため，得られる情報はそれらの平均に対応していた．しかし実際には，室温・溶液中などで光応答性タンパク質のような巨大な分子の構造は常に揺らいでいるため，平均として得られる情報が分子本来の特性とどのように結びついているのかは自明ではなかった．本研究では，こうした従来の“平均を観る”分光法から得られるデータに隠れていた，個々の分子本来の情報を炙り出す新規な方法論を新たに開拓したという点において，高い学術的意義を持つ．