The Structure of the Aggregate Form of Bacteriochlorophyll c Showing the Qy Absorption above 740 nm as Determined by the Ring‐current Effects on 1H and 13C Nuclei and by 1H–1H Intermolecular NOE Correlations
The Structure of the Aggregate Form of Bacteriochlorophyll c Showing the Qy Absorption above 740 nm as Determined by the Ring‐current Effects on 1H and 13C Nuclei and by 1H–1H Intermolecular NOE Correlations
复制标题
细菌叶绿素 c 聚集体的结构，显示 740 nm 以上的 Qy 吸收，由 1H 和 13C 核环电流效应以及 1H-1H 分子间 NOE 相关性确定
DOI：
10.1111/j.1751-1097.1998.tb05193.x
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发表时间：
1998
影响因子：
3.3
通讯作者：
F. Inagaki
中科院分区：
文献类型：
--
作者：
T. Mizoguchi;S. Sakamoto;Y. Koyama;K. Ogura;F. Inagaki
将富含13C的细菌叶绿素c （S[I, E] BChl cF）悬浮在二氯甲烷和四氯化碳的1:3混合物中，形成聚集体，在740 nm以上表现出Qy吸收；当滴定甲醇溶解聚集体时，13C化学位移的变化被追踪，然后，这些变化与聚集体中邻近大环的环电流效应相关。基于环电流对1H和13C核的影响，提出了一对聚集体结构；单体单元堆叠在一起，形成具有不同滑动方向的倾斜柱，其中分子的y轴平行于柱的长轴。为了验证这对模型，在磁偶极子近似和环电流近似的基础上计算了环电流对1H和13C核的影响。此外，将三维F1 - 13C编辑的F3 - 13C过滤的异核单量子相关-核Overhauser效应光谱应用于上述由13C标记和未标记的BChl c组成的1:1混合物的聚集体，成功地选择性地检测了1H-1H分子间核Overhauser效应相关性，从而确定了上述对堆叠结构在聚集体中的共存。
13C‐enriched bacteriochlorophyll c (S[I, E] BChl cF) was suspended in a 1:3 mixture of methylene chloride and carbon tetrachloride to form an aggregate showing the Qy absorption above 740 nm; changes in the 13C chemical shifts were traced when methanol was titrated to dissolve the aggregate, and then, the changes were correlated to the ring‐current effects due to the neighboring macrocycles in the aggregate. A pair of aggregate structures has been proposed based on the ring‐current effects on both 1H and 13C nuclei; the monomeric units are stacked together to form an inclined column with different sliding directions, in which the y‐axis of the molecule is parallel to the long axis of the column. In order to confirm this pair of models, the ring‐current effects on the 1H and 13C nuclei were calculated based on both the magnetic‐dipole and the loop‐current approximations. Further, an application of three‐dimensional F1 13C‐edited F3 13C‐filtered heteronuclear single‐quantum correlation‐nuclear Overhauser effect spectroscopy to the above aggregate consisting of a 1:1 mixture of 13C‐labeled and unlabeled BChl c succeeded in detecting selectively the 1H–1H intermolecular nuclear Overhauser effect correlations, which established the coexistence of the above pair of stacked structures in the aggregate.