Femtosecond Structural Study for Visualization of the Primary Dynamics of Photoreceptor Proteins

2015 Fiscal Year Final Research Report

• Project/Area Number: 25248009
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Takeuchi Satoshi 国立研究開発法人理化学研究所, 田原分子分光研究室, 専任研究員 (50280582)
• Co-Investigator(Renkei-kenkyūsha): KAMIKUBO Hironari 奈良先端科学技術大学院大学, 物質創成科学研究科, 准教授 (20311128)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 時間分解分光 / ラマン散乱 / 光受容タンパク質 / フェムト秒 / 水素結合 / 光異性化

Outline of Final Research Achievements

We elucidated the initial events of photoreceptor proteins at the molecular level using femtosecond time domain Raman spectroscopy that has been graded up to the ultimate level. The data obtained from photoactive yellow protein showed ultrafast changes in the low-frequency Raman signals, indicating that the hydrogen bond between the chromophore and adjacent amino acid residue is weakened in 100 fs after photoabsorption. It was also shown that the chromophore retains its initial trans conformation during the excited state lifetime, whereas it has a distorted cis conformation in the first ground state intermediate. In addition, we developed a new method, two dimensional femtosecond Raman excitation profile spectroscopy, and succeeded in visualizing the structural evolution of excited state molecules in ultrafast photoisomerization.

Free Research Field

分子分光学