光合成反応センターの光学吸収断面の再設計
Palash K Dutta1, Su Lin, Andrey Loskutov
1Department of Chemistry and Biochemistry and ‡The Biodesign Institute, Arizona State University , Tempe, Arizona 85287, United States.
Journal of the American Chemical Society
|February 27, 2014
まとめ
研究者は染料分子をバクテリアの反応センターに組み込み,光収集を改善した. この人工アンテナシステムは,電荷分離を強化し,より効率的な人工光合成の道を開きました.
科学分野:
- バイオケミストリーとバイオ物理学
- 光合成研究 研究 光合成研究
- 人工光合成による合成です.
背景:
- Rhodobacter sphaeroidesのような紫色の光合成細菌の反応センター (RC) は,光エネルギーを化学エネルギーに変換するのに不可欠です.
- 効率的な光収集は,生物学的および人工的なシステム内のエネルギー転送を最適化するための鍵です.
研究 の 目的:
- 人工アンテナシステムから細菌反応センターへの効率的なエネルギー転送のためのスペクトルおよび幾何学的要件を調査する.
- RC機能を強化するための人工アンテナシステムとして,共振結合染料分子の可能性を調査する.
主な方法:
- Rhodobacter sphaeroides RCのエンジニアリングされたシステイン残留物は,Alexa Fluor染料 (660,647,750) と結合されました.
- 安定状態と時間解像度の光スペクトロスコピーを用いた.
- トランジエント吸収スペクトロスコピーは,エネルギー伝送と電荷分離のダイナミクスを分析するために使用されました.
主要な成果:
- 平均2.5個のAlexa Fluor 660染料分子がRCに結合すると,吸収率の横断面が著しく増加しました.
- 650nmでの刺激で,電荷分離状態形成の2.2倍の増加が観察されました.
- この研究では,染料からRCへのエネルギー転送効率を制御する重要なパラメータを特定しました.
結論:
- 光染料をバクテリアの反応センターに共振的に結合することで,光の吸収と電荷分離の効率が向上します.
- この研究は,自然反応センターと統合された高度な人工光採集システムを設計するための重要な洞察を提供します.
さらに関連する動画
11:55In Vitro Reconstitution of Light-harvesting Complexes of Plants and Green Algae
Published on: October 10, 2014
18.4K
08:40Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
Published on: February 14, 2019
7.2K
関連する概念動画
The Photochemical Reaction Center
4.4K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
4.4K
Photosystem II
59.9K
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
59.9K
The Antenna Complex
6.9K
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
6.9K
The Z-Scheme of Electron Transport in Photosynthesis
12.6K
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
12.6K
Photosystem I
52.8K
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
52.8K
The Calvin Benson Cycle
6.3K
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
6.3K
