title: Phosphate ion targeted colorimetric and fluorescent probe and its use to monitor endogeneous phosphate ion in a hemichannel-closed cell.
abstract: Fluorescent probe 1, the first inorganic phosphate (Pi) targeted colorimetric and fluorescent probe to detect endogenous Pi in hemichannel-closed cells, has been developed. Probe 1 undergoes a unique Pi induced hydrolytic reaction in DMSO-HEPES (V/V = 9:1) buffered (0.02 M, pH 7.4) solutions that produces a colorimetric change associated with a 62 nm red-shift in the UV-vis absorption maximum and up to a 780-fold enhancement in the fluorescence intensity. The mechanistic proposal that these spectroscopic changes are associated with reaction Pi with 1 to form coumarin gains support from the results of theoretical calculations and mass spectrometry studies. Observations made in fluorescence imaging studies with HeLa cells and C. elegans show that 1 can be employed to monitor Pi production in vivo caused by apyrase-catalyzed ATP hydrolysis. Moreover, probe 1 was utilized to show that apoptosis of hemichannel-closed Sf9 cells is caused by Inx3 promoted dephosphorylation of Akt (RAC serine/threonine-protein kinase), leading to an elevation of the concentration of Pi. Overall, the study has produced the first fluorescent sensor 1 for endogenous inorganic phosphate. Moreover, the utility of 1 for measuring Pi release in vitro has been demonstrated and utilized to elucidate the mechanism of Inx3 action in hemichannel-closed Sf9 cells.
authors.affiliation: College of Chemical Science and Technology, Yunnan University , Kunming 650091, China.
authors.forename: Lin E
authors.initials: LE
authors.lastname: Guo
authors.forename: Jun Feng
authors.initials: JF
authors.lastname: Zhang
authors.forename: Xin Yi
authors.initials: XY
authors.lastname: Liu
authors.forename: Li Mei
authors.initials: LM
authors.lastname: Zhang
authors.forename: Hong Li
authors.initials: HL
authors.lastname: Zhang
authors.forename: Jian Hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Xiao Guang
authors.initials: XG
authors.lastname: Xie
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Kaijun
authors.initials: K
authors.lastname: Luo
authors.forename: Juyoung
authors.initials: J
authors.lastname: Yoon
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D017173:Caenorhabditis elegans / Q000378:metabolism; D002460:Cell Line; D003124:Colorimetry; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis; D008958:Models, Molecular; D061848:Optical Imaging; D010710:Phosphates / Q000032:analysis* / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D010710:Phosphates; D000255:Adenosine Triphosphate