Functional analysis of photosynthetic proteins by photoelectrochemistry-quartz crystal microbalance simultaneous measurement

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K21077
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bio-related chemistry; Polymer chemistry
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Kondo Masaharu 名古屋工業大学, 工学(系)研究科(研究院), 助教 (20571219)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 水晶発振子

Outline of Final Research Achievements

In this study, we immobilized the photosynthetic reaction protein LH1-RC from a photosynthetic bacterium on a quartz crystal microbalance (QCM) sensor chip to observe the adsorption/desorption of molecules that exchanges electrons with LH1-RC by simultaneously measurements, QCM and photocurrent measurements. When the LH1-RC was immobilized on a QCM sensor chip surface-modified with an amino group and simultaneous measurement experiments were conducted, the photocurrent density was low because the amount of LH1-RC immobilized was very small. Since the photocurrent response was buried in the noise to the electrochemical measuring instrument, the evaluation in the simultaneous measurement system could not be performed with a sufficient signal. In a system using a conductive oxide substrate instead of a gold substrate, an increase in photocurrent density was confirmed by changing the concentration of electron acceptor; water-soluble ubiquinone and electron donor; cytochrome c.

Free Research Field

生体関連化学

Academic Significance and Societal Importance of the Research Achievements

生物が行なう光合成反応では、光エネルギーを利用して電子を移動させる(光誘起電流を発生させる)反応中心RCが、電子受容体・供与体の分子と協同的にはたらくことで、高効率の光誘起電子移動を実現している。本研究では、RCとコアアンテナタンパク質(LH1)との複合体LH1-RCを水晶発振子上へ分子配向を制御し、活性を保ったまま固定化し、電気化学計測による光誘起電流とLH1-RCと電子の授受をする分子のLH1-RCへの吸脱着による重量変化をQCMの同時計測により基板上に固定化されたLH1-RCの機能・物性の評価を行なう。この評価で得られた知見から、生体高分子を用いた光水素生産デバイスの構築を目指す。