Photolysis of a protecting group for the carboxyl function of neurotransmitters within 3 microseconds and with product quantum yield of 0.2.
Photolysis of a protecting group for the carboxyl function of neurotransmitters within 3 microseconds and with product quantum yield of 0.2.
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在 3 微秒内光解神经递质羧基功能的保护基团，产物量子产率为 0.2。
DOI：
10.1073/pnas.90.23.11074
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发表时间：
1993
影响因子：
11.1
通讯作者：
Hess,GP
中科院分区：
文献类型：
--
作者：
Ramesh,D;Wieboldt,R;Niu,L;Carpenter,BK;Hess,GP
报道了神经递质羧基功能的光敏封闭基团的合成，在这种情况下，甘氨酸。该化合物为2-甲氧基-5-硝基苯甘氨酸酯(笼状甘氨酸)，在308或337 nm的激光脉冲作用下，3微秒内光解，产物量子产率为0.2。该化合物在pH为7.1的水溶液中水解度为6.1分钟，在pH为4.0的水溶液中水解度为3小时。含有甘氨酸受体的小鼠大脑皮层神经元被用于生物学检测。在细胞流动装置中，将pH为4.0的笼状甘氨酸溶液与缓冲液混合，得到最终的pH为7.1，用来平衡化合物与细胞表面的受体。笼状化合物和2-甲氧基-5-硝基苯酚光解产物都不影响甘氨酸受体，也不改变它们对甘氨酸的反应。当用337 nm的激光脉冲照射与笼状甘氨酸平衡的细胞时，如全细胞电流记录所检测的那样，甘氨酸受体通道被打开。所描述的方法可用于合成和表征神经递质的耐光性前体和其他含有羧基的化合物，以及在微秒时间域内对中枢神经系统细胞中的神经递质受体进行动力学研究。
The synthesis of a photosensitive blocking group for the carboxyl function of neurotransmitters, in this case glycine, is reported. The compound, 2-methoxy-5-nitrophenyl glycine ester (caged glycine), is photolyzed by a laser pulse at 308 or 337 nm within 3 microseconds and with a product quantum yield of 0.2. The compound is hydrolyzed in water with a time constant tau of 6.1 min at pH 7.1 and 3 hr at pH 4.0. Mouse cerebral cortical neurons containing glycine receptors were used in biological assays. A cell-flow device, in which solutions of caged glycine at pH 4.0 were mixed with buffer to give a final pH of 7.1, was used to equilibrate the compound with receptors on the cell surface. Neither the caged compound nor the 2-methoxy-5-nitrophenol photolysis product affected the glycine receptors or modified their response to glycine. When cells equilibrated with caged glycine are irradiated by a laser pulse at 337 nm, glycine receptor channels are opened, as detected in whole-cell current recordings. The approach described may be used in the synthesis and characterization of photolabile precursors of neurotransmitters and other compounds that contain carboxyl groups and for kinetic investigations of neurotransmitter receptors in central nervous system cells in the microsecond time domain.