Supramolecular Architecture and Function of Photosynthetic Units in Chloroplasts

在受控条件下发育的叶绿体中，光合单位的形成受到监测。通过光系统复合物的定量、原位Chl天线大小和组成的测量、与多肽亚基组成的相关性以及免疫印迹分析，研究了PSII光收集复合物中四种不同的含Chl a和Chl b多肽的组装和组织。此外，还对3个新的低分子量蛋白（12-19 kDa区）的起源、生理意义和功能进行了研究。在PSU的组装/发育过程中，这些在类囊体膜中大量存在，但在成熟的叶绿体中基本没有。实验旨在分离这三种新蛋白并形成针对各自多肽的抗体。后续研究将探讨这些蛋白在类囊体膜上的免疫交叉反应性、化学交联性和定位。太阳能是地球上所有生物能源的最终来源，它是通过绿色植物光合单位中的叶绿素吸收光转化为化学形式的。本研究阐明了该单位在绿色植物叶绿体中的结构和功能，并为光合单位的组装/组织提供了信息。这将导致对生物能量转换过程中的光利用的理解。

The formation of the photosynthetic unit is being monitored in chloroplasts developing under controlled conditions. The assembly and organization of four distinct Chl a and Chl b- containing polypeptides in the light-harvesting complex of PSII are being studied by quantitation of photosystem complexes, measurement of the Chl antenna size and composition in situ, correlation with polypeptide subunit composition, and immunoblot analysis. In addition, the origin, physiological significance and function of three novel low molecular-weight proteins (12-19 kDa region) are being studied. These are abundant in the thylakoid membrane during the assembly/development of the PSU but are largely absent from the mature chloroplast. Experiments are designed for the isolation of the three novel proteins and for the formation of antibodies against the respective polypeptides. Subsequent research will investigate the immunological cross- reactivity, chemical cross-linking and localization of these proteins in the thylakoid membrane. Solar energy, the ultimate source of all biological energy on this planet, is converted to chemical form through absorption of light by chlorophyll in the photosynthetic unit of green plants. This research is elucidating the architecture and function of this unit in green plant chloroplasts and is providing information on the assembly/organization of the photosynthetic unit. It will lead to an understanding of light utilization in a biological energy conversion process.