对氨与光系统II的氧气演化复合体结合的模型的综合评估
Maria Drosou1,2, Dimitrios A Pantazis1
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany.
The journal of physical chemistry. B
|February 1, 2024
概括
研究氨与氧演化复合体 (OEC) 的结合,揭示了它的基质通路. 氨在Mn4集群上取代终端水联体的氨最符合实验数据,澄清了水氧化机制.
科学领域:
- 生物化学和生物物理学
- 光合作用研究研究 光合作用研究
- 计算化学计算化学
背景情况:
- 了解光合作用中的氧进化复合体 (OEC) 机制对于水的氧化至关重要.
- 氨作为一种水类模拟物,用于探测基质访问和O-O键形成途径.
- 之前的研究提出了氨的五种结合方式,但并非所有都与光谱数据进行了计算验证.
研究的目的:
- 通过使用统一的理论方法,评估所有拟议的第一球氨与OEC在其S2状态中的结合模式.
- 通过将计算结果与实验光谱数据进行比较,确定最合理的氨相互作用模型.
主要方法:
- 采用一致的理论框架和计算方法来建模氨-OEC相互作用.
- 评估了拟议的氨结合模型的能量,磁,运动和光谱特性.
- 将理论预测与实验电子磁共振 (EPR),电子核双共振 (ENDOR),电子自旋回声封膜调制 (ESEEM) 和电子电子双共振 (EDNMR) 数据进行了比较.
主要成果:
- 在Mn4位点上氨取代了两个终端水联体之一的模型显示与实验光谱数据的最强一致.
- 这些结果绝对排除了桥梁μ-oxo连接体的氨基替代.
- 同样不包括将氨作为Mn1或Mn4上的第六个联结体的模型.
结论:
- 氨与OEC的相互作用,特别是取代终端水联体,为基质通路提供了关键的见解.
- 这项研究完善了我们对OEC活性部位及其在水氧化中的作用的理解.
- 这些发现有助于阐明光合作用过程中氧气进化的机制.
更多相关视频
相关概念视频
Protein and Protein Structure
79.6K
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme...
A protein's shape is critical to its function. For example, an enzyme...
79.6K
The Photochemical Reaction Center
4.1K
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...
4.1K
The Antenna Complex
6.0K
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...
6.0K
Molecular Models
38.4K
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
38.4K
Ladder Diagrams: Complexation Equilibria
350
Ladder diagrams are useful for evaluating equilibria involving metal-ligand complexes. The vertical scale of the ladder diagram represents the concentration of unreacted or free ligand, pL. The horizontal lines on the scale depict the log of stepwise formation constants for metal-ligand complexes and indicate the dominant species in all the regions.
The formation constant, K1, for the formation of Cd(NH3)2+ complex from cadmium and ammonia is 3.55 × 102. Log K1 (i.e. pNH3) is 2.55, and...
The formation constant, K1, for the formation of Cd(NH3)2+ complex from cadmium and ammonia is 3.55 × 102. Log K1 (i.e. pNH3) is 2.55, and...
350
Cooperative Allosteric Transitions
7.9K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
7.9K
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)

