Pick Annika M, Weber Kristin, Jakobs Marisa F, Carlsson Max J, Wittmann Simon, Fahrer Jörg, Becker Sabine
Department of Chemistry, RPTU Kaiserslautern-Landau, Erwin-Schroedinger-Str. 54, Kaiserslautern 67663, Germany.
Division of Food Chemistry and Toxicology, Department of Chemistry, RPTU Kaiserslautern-Landau, Erwin-Schroedinger-Str. 52, Kaiserslautern 67663, Germany.
ACS Omega. 2025 Jul 25;10(30):33629-33635. doi: 10.1021/acsomega.5c04186. eCollection 2025 Aug 5.
Pools of labile bound zinc ions are essential for signal transduction in the human body. At the cellular level, such pools occur in the cytosol, discrete organelles, and secretory vesicles. These zinc-containing vesicles are found in distinct regions of the central nervous system, modulating calcium ion channels that play an essential role in olfaction, audition, and somatosensory perception. Dysregulation of these receptors is associated with a number of neurodegenerative diseases. To understand the underlying mechanisms at the molecular level, zinc fluorescence sensors are versatile tools. In this report, a new member of the spiropyran-based sensor family SpiroZin, which has proven useful for the investigation of zinc in living cells, is presented: SpiroZin2-COOH. This sensor can be synthesized in a 5-step synthesis and shows superior zinc-sensing properties in cuvette as well as live cell studies. The quantum yield is approximately seven times higher than that of the parent zinc sensor, which also results in an approximately 6-fold higher brightness and a turn-on of 30 at pH 7 in cuvette studies. Another advantage is a significant red-shift of 30 nm in comparison to the parent sensor SpiroZin2. Other basic properties of the SpiroZin family are retained, as revealed by a similar binding constant and negligible pH dependence in zinc sensing. Similar to other members of the SpiroZin family, SpiroZin2-COOH images intracellular zinc pools in living cells. Lysotracker costaining reveals lysosomal localization of SpiroZin2-COOH. The turn-on is determined to be 14.6, which is the highest turn-on within the SpiroZin family reported so far in live-cell studies.
不稳定结合锌离子池对于人体信号转导至关重要。在细胞水平上，此类锌离子池存在于细胞质溶胶、离散细胞器和分泌小泡中。这些含锌小泡存在于中枢神经系统的不同区域，调节在嗅觉、听觉和体感感知中起关键作用的钙离子通道。这些受体的失调与多种神经退行性疾病相关。为了在分子水平上理解其潜在机制，锌荧光传感器是多功能工具。在本报告中，介绍了基于螺吡喃的传感器家族SpiroZin的一个新成员，它已被证明可用于活细胞中锌的研究：SpiroZin2-COOH。该传感器可通过五步合成法制备，并且在比色皿以及活细胞研究中显示出优异的锌传感特性。其量子产率比母体锌传感器高约七倍，这也导致在比色皿研究中亮度提高约6倍，在pH 7时开启倍数为30。另一个优点是与母体传感器SpiroZin2相比有30 nm的显著红移。正如锌传感中相似的结合常数和可忽略的pH依赖性所揭示的那样，SpiroZin家族的其他基本特性得以保留。与SpiroZin家族的其他成员类似，SpiroZin2-COOH可对活细胞内的锌离子池成像。溶酶体追踪剂共染色显示SpiroZin2-COOH定位于溶酶体。开启倍数测定为14.6，这是迄今为止在活细胞研究中报道的SpiroZin家族中最高的开启倍数。
