溶液和生物相关的形状的异构体11-cis-locked环烯基网膜
Yukari Fujimoto1, Nathan Fishkin, Gennaro Pescitelli
1Department of Chemistry, Columbia University, New York, New York 10027, USA.
Journal of the American Chemical Society
|June 20, 2002
概括
研究人员使用新的双循环视网膜类似物研究了牛素中的11-cis-retinylidene染色体. 只有β-cyclopropyl enantiomer (2a) 与素结合,揭示了对受体内的染色体结合和构造的洞察力.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 频谱学是一种光谱学.
背景情况:
- 了解11-cis-retinylidene染色体在牛素中的构造对于视觉色素功能至关重要.
- 与聚烯系统相关的状环基团对手术贡献的理解很差.
研究的目的:
- 为了研究与opsin.r结合的11-cis锁定的bicyclo[5.1.0]octyl视网膜 (retCPr) 的形状.
- 为了澄清连接到聚烯系统的环环的手术贡献.
- 为了确定retCPr enantiomers对opsin的结合选择性.
主要方法:
- 合成和表征11-cis锁定双循环[5.1.0]八状视网膜 (retCPr) 的等离子体.
- 核磁共振 (NMR) 光谱法用于确定环形状.
- 计算方法 (几何优化,CD计算) 来建模结构.
- 素结合试验用于评估反体选择性.
主要成果:
- 核磁共振揭示了 retCPr 七分之一环的扭动椅形状.
- 计算分析显示,反体2a存在于C12-C13周围的正扭曲的异体中.
- 只有β-cyclopropyl enantiomer (2a) 能与素结合,而不是α-enantiomer (2b).
- 环烯基部分对染色体的结合作用是最小的.
结论:
- 染色体与opsin的N端结合,从4-甲和15- aldehyde侧进入.
- 奥普辛的结合裂容纳了11-cis-视网膜,在C12-C13周围略有正转.
- 这种构造解释了retCPr 2a观察到的生物立体选择性,并重新解释了以前的光谱数据.
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