Chemistry Division, Argonne National Laboratory, 60439, Argonne, IL, USA.
Photosynth Res. 1990 Dec;26(3):143-60. doi: 10.1007/BF00033128.
The author gives an autobiographical sketch of his path to chlorophyll research, and describes some results. The discussion is largely focused on long wavelength forms of chlorophyll and how they might be generated by self-assembly. Dimers or oligomers, (Chl)n, result from coordination interactions between the central magnesium atom of one macrocycle and nucleophilic side chains of another i.e., keto C=O⋯Mg in the case of Chl a. Coordination interactions mediated by a water molecule coordinated to Mg in one macrocycle and to a nucleophilic group in another e.g., Mg⋯O(H)H⋯O=C keto, form aggregates with very different structures and properties; where more than one strong nucleophile or hydrogen bonding group is present in the chlorophyll, e.g., the formyl group in Chl b, the acetyl group of Bchl a, or the hydroxyethyl group of Bchl c, they may also participate in direct coordination interactions with Mg as well as hydrogen bonding to water coordinated to Mg. The magnetic resonance properties of Chl a/water aggregates have provided the basis for the special pair concept for the primary electron donor in photosynthesis. Structural information derived from small angle neutron scattering studies on chlorophyll aggregates is now providing an experimental basis for comprehensive models that integrate antenna and photoreaction center chlorophyll functions.
作者对其叶绿素研究之路进行了自传式的简述，并描述了一些研究成果。讨论主要集中在长波长形式的叶绿素以及它们如何通过自组装产生。二聚体或寡聚体（Chl）n 是由一个大环的中心镁原子与另一个大环的亲核侧链之间的配位相互作用产生的，例如 Chl a 中的酮羰基⋯Mg。由一个水分子中介的配位相互作用，该水分子在一个大环中与另一个亲核基团配位，例如 Mg⋯O（H）H⋯O=C 酮，形成具有非常不同结构和性质的聚集体；在叶绿素中存在不止一个强亲核基团或氢键供体，例如 Chl b 中的甲酰基、Bchl a 的乙酰基或 Bchl c 的羟乙基，它们也可能与 Mg 发生直接配位相互作用，并与配位到 Mg 的水分子形成氢键。Chl a/水聚集体的磁共振性质为光合作用中初级电子供体的特殊对概念提供了基础。从小角中子散射研究叶绿素聚集体获得的结构信息，为整合天线和光反应中心叶绿素功能的综合模型提供了实验基础。
