A Fluorescent Sensor for GABA and Synthetic GABAB Receptor Ligands
摘要:
While gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter, suitable tools to measure its concentration in living cells with high spatiotemporal resolution are missing. Herein, we describe the first ratiometric fluorescent sensor for GABA, dubbed GABA-Snifit, which senses GABA with high specificity and spatiotemporal resolution on the surface of living mammalian cells. GABA-Snifit is a semisynthetic fusion protein containing the GABA(B) receptor, SNAP- and CLIP-tag, a synthetic fluorophore and a fluorescent GABA(B) receptor antagonist. When assembled on cell surfaces, GABA-Snifit displays a GABA-dependent fluorescence emission spectrum in the range of 500-700 nm that permits sensing micromolar to millimolar GABA concentrations. The ratiometric change of the sensor on living cells is 1.8. Furthermore, GABA-Snifit can be utilized to quantify the relative binding affinities of GABA(B) receptor agonists, antagonists and the effect of allosteric modulators. These properties make GABA-Snifit a valuable tool to investigate the role of GABA and GABA(B) in biological systems.
Synthesis of new benzo[a]phenoxazinium probes possessing carboxylic ester, hydroxyl and amino functional groups: Photophysical studies in dry ethanol and conjugation with CdTe quantum dots
作者:B. Rama Raju、Arlindo M. Fontes Garcia、A. Luísa S. Costa、Paulo J.G. Coutinho、M. Sameiro T. Gonçalves
DOI:10.1016/j.dyepig.2014.04.006
日期:2014.11
A Fluorescent Sensor for GABA and Synthetic GABA<sub>B</sub> Receptor Ligands
While gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter, suitable tools to measure its concentration in living cells with high spatiotemporal resolution are missing. Herein, we describe the first ratiometric fluorescent sensor for GABA, dubbed GABA-Snifit, which senses GABA with high specificity and spatiotemporal resolution on the surface of living mammalian cells. GABA-Snifit is a semisynthetic fusion protein containing the GABA(B) receptor, SNAP- and CLIP-tag, a synthetic fluorophore and a fluorescent GABA(B) receptor antagonist. When assembled on cell surfaces, GABA-Snifit displays a GABA-dependent fluorescence emission spectrum in the range of 500-700 nm that permits sensing micromolar to millimolar GABA concentrations. The ratiometric change of the sensor on living cells is 1.8. Furthermore, GABA-Snifit can be utilized to quantify the relative binding affinities of GABA(B) receptor agonists, antagonists and the effect of allosteric modulators. These properties make GABA-Snifit a valuable tool to investigate the role of GABA and GABA(B) in biological systems.
Benzo[a]phenoxazinium chlorides: Synthesis, antifungal activity, in silico studies and evaluation as fluorescent probes
作者:Maria Inês P.S. Leitão、B. Rama Raju、Nuno M.F.S.A. Cerqueira、Maria João Sousa、M. Sameiro T. Gonçalves
DOI:10.1016/j.bioorg.2020.103730
日期:2020.5
other benzo[a]phenoxaziniumchlorides. Minimum Inhibitory Concentration (MIC) values between 1.56 and >200 µM were observed. Fluorescence microscopy studies, used to assess the intracellular distribution of the dyes, showed that these benzo[a]phenoxaziniumchlorides function as efficient and site specific probes for the detection of the vacuole membrane. The added advantage of some of the compounds