A new generation of fluorescent ion indicators for measuring cytosolic concentrations of calcium. These new indicators emit in the red portion of the visible spectrum and are ratiometric. The ratiometry consists of shifting in the emission upon binding calcium when exciting with an argon laser at 488 nm. These indicators also show marked increases in red fluorescence when excited with visible light at longer wavelengths. Like all calcium indicators, they comprise the usual chelating portion based on BAPTA (Bis Amino Phenyl Tetraacetic Acid) and a fluorophore portion, either a seminaphthofluorescein/seminaphthorhodamine or dinaphthofluorescein, which enable ratiometry. Unlike other naphthofluoresceins, the pKa has been adjusted on the naphtho moiety to make it suitable for biological calcium measurements. The invention relates to the structures of the indicators and to the method of synthesizing these indicators.
一种新一代荧光离子指示剂,用于测量细胞质
钙离子浓度。这些新指示剂在可见光谱的红色部分发射,具有比例测量功能。比例测量是指当激发波长为488纳米的
氩激光结合
钙离子时,发射波长发生移动。这些指示剂在用长波长的可见光激发时,也表现出明显的红色荧光增加。与所有
钙指示剂一样,它们包括基于BA
PTA(双
氨基苯基
四乙酸)的通常螯合部分和荧光部分,可以是一种半
萘荧光素/半
萘红
荧光素或二
萘荧光素,以实现比例测量。与其他
萘荧光素不同的是,
萘基部分的pKa已经调整,使其适用于
生物钙测量。本发明涉及指示剂的结构和合成方法。