THE PHOTOSYNTHETIC CHROMATOPHORE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 色团是一个假细胞器，负责收集光线和随后的转化。 将光能转化为三磷酸腺苷(http://www.ks.uiuc.edu/Research/psures).)形式的化学能初始激磁后 从发色团中的捕光蛋白质对光子的吸收，激发能量在 多步骤过程到反应中心(RC)。在RC处，激发能被用来给苯二酚分子充电，这 然后通过富含蛋白质的色团膜扩散到BC$1$。在那里带电的苯二酚被氧化了哟 在膜上产生质子梯度，进而通过三磷酸腺苷合成酶驱动三磷酸腺苷的产生。在紫色细菌中， 例如球形红杆菌，负责捕获光子的蛋白质被称为捕光复合体1 (LH1)和捕光复合体2(LH2)。LH1与在发色团中发现的另外两种蛋白质RC和 PufX，形成LH1-RC-PufX二聚体复合体。LH2和LH1-RC-PufX具有双重功能；它们不仅负责 通过捕捉光能，它们还诱导膜弯曲，将发色团塑造成小泡或管状。 因此，该系统关系到理解生物物理学中的两个基本问题，即膜 Moronegens和细胞能量生产。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The chromatophore is a pseudo-organelle that is responsible for harvesting light and subsequent conversion of light energy to chemical energy in the form of ATP (http://www.ks.uiuc.edu/Research/psures). After initial excitation from photon absorption by the light harvesting proteins in the chromatophore, excitation energy is tranferred in a multi-step process to a reaction center (RC). At the RC the excitation energy is used to charge a quinone molecule, which then diffuses through the protein-rich chromatophore membrane to a bc$_1$. There the charged quinone is oxidized yo produce a proton gradient across the membrane, which in turn drives ATP production by ATP synthase. In purple bacteria, such as Rhodobacter sphaeroides, the protein responsible for photon capture are known as light harvesting complex 1 (LH1) and light harvesting complex 2 (LH2). LH1 associates with two other proteins found in the chromatophore, RC and PufX, to form LH1-RC-PufX dimer complexes. LH2 and LH1-RC-PufX have a dual function; not only are they responsible for capturing light energy, they also induce membrane curvature to shape the chromatophore into, e.g., vesicles or tubes. Therefore, the systemis relevant to understand two fundamental questions in biophysics, namely membrane morphonegensis and cellular energy production.