Zinspy sensors with enhanced dynamic range for imaging neuronal cell zinc uptake and mobilization.
Thiophene moieties were incorporated into previously described Zinspy (ZS) fluorescent Zn(II) sensor motifs (Nolan, E. M.; Lippard, S. J. Inorg. Chem. 2004, 43, 8310-8317) to provide enhanced fluorescence properties, low-micromolar dissociation constants for Zn(II), and improved Zn(II) selectivity. Halogenation of the xanthenone and benzoate moieties of the fluorescein platform systematically modulates the excitation and emission profiles, pH-dependent fluorescence, Zn(II) affinity, and Zn(II) complexation rates, offering a general strategy for tuning multiple properties of xanthenone-based metal ion sensors. Extensive biological studies in cultured cells and primary neuronal cultures demonstrate 2-{6-hydroxy-3-oxo-4,5-bis[(pyridin-2-ylmethylthiophen-2-ylmethylamino)methyl]-3H-xanthen-9-yl}benzoic acid (ZS5) to be a versatile imaging tool for detecting Zn(II) in vivo. ZS5 localizes to the mitochondria of HeLa cells and allows visualization of glutamate-mediated Zn(II) uptake in dendrites and Zn(II) release resulting from nitrosative stress in neurons.
Nolan
Elizabeth M
EM
Department of Chemistry, Picower Institute of Learning and Memory, RIKEN-MIT Neuroscience Research Center, and Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Ryu
Jubin W
JW
Jaworski
Jacek
J
Feazell
Rodney P
RP
Sheng
Morgan
M
Lippard
Stephen J
SJ
D000818:Animals; D015374:Biosensing Techniques; D019556:COS Cells; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D018360:Crystallography, X-Ray; D018891:Dentate Gyrus / Q000166:cytology; D005452:Fluoresceins / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D018698:Glutamic Acid / Q000494:pharmacology; D006367:HeLa Cells; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D018613:Microscopy, Confocal; D015394:Molecular Structure; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D015032:Zinc / Q000032:analysis* / Q000378:metabolism
D005452:Fluoresceins; D018698:Glutamic Acid; D015032:Zinc