56883-17-1Relevant academic research and scientific papers
Organelle-specific detection of phosphatase activities with two-photon fluorogenic probes in cells and tissues
Li, Lin,Ge, Jingyan,Wu, Hao,Xu, Qing-Hua,Yao, Shao Q.
experimental part, p. 12157 - 12167 (2012/09/22)
Two-photon fluorescence microscopy (TPFM) provides key advantages over conventional fluorescence imaging techniques, namely, increased penetration depth, lower tissue autofluorescence and self-absorption, and reduced photodamage and photobleaching and therefore is particularly useful for imaging deep tissues and animals. Enzyme-detecting, small molecule probes provide powerful alternatives over conventional fluorescent protein (FP)-based methods in bioimaging, primarily due to their favorable photophysical properties, cell permeability, and chemical tractability. In this article, we report the first fluorogenic, small molecule reporter system (Y2/Y1) capable of imaging endogenous phosphatase activities in both live mammalian cells and Drosophila brains. The one- and two-photon excited photophysical properties of the system were thoroughly investigated, thus confirming the system was indeed a suitable Turn-ON fluorescence pair for TPFM. To our knowledge, this is the first enzyme reporting two-photon fluorescence bioimaging system which was designed exclusively from a centrosymmetric dye possessing desirable two-photon properties. By conjugation of our reporter system to different cell-penetrating peptides (CPPs), we were able to achieve organelle- and tumor cell-specific imaging of phosphatase activities with good spatial and temporal resolution. The diffusion problem typically associated with most small molecule imaging probes was effectively abrogated. We further demonstrated this novel two-photon system could be used for imaging endogenous phosphatase activities in Drosophila brains with a detection depth of >100 μm.
Multicolor, one- and two-photon imaging of enzymatic activities in live cells with fluorescently quenched activity-based probes (qABPs)
Hu, Mingyu,Li, Lin,Wu, Hao,Su, Ying,Yang, Peng-Yu,Uttamchandani, Mahesh,Xu, Qing-Hua,Yao, Shao Q.
supporting information; experimental part, p. 12009 - 12020 (2011/09/21)
Fluorescence imaging provides an indispensable way to locate and monitor biological targets within complex and dynamic intracellular environments. Of the various imaging agents currently available, small molecule-based probes provide a powerful tool for live cell imaging, primarily due to their desirable properties, including cell permeability (as a result of their smaller sizes), chemical tractability (e.g., different molecular structures/designs can be installed), and amenability to imaging a wide variety of biological events. With a few exceptions, most existing small molecule probes are however not suitable for in vivo bioimaging experiments in which high-resolution studies of enzyme activity and localization are necessary. In this article, we reported a new class of fluorescently Quenched Activity-Based Probes (qABPs) which are highly modular, and can sensitively image (through multiple enzyme turnovers leading to fluorescence signal amplification) different types of enzyme activities in live mammalian cells with good spatial and temporal resolution. We have also incorporated two-photon dyes into our modular probe design, enabling for the first time activity-based, fluorogenic two-photon imaging of enzyme activities. This, hence, expands the repertoire of smart, responsive probes currently available for live cell bioimaging experiments.
A self-immobilizing and fluorogenic unnatural amino acid that mimics phosphotyrosine
Ge, Jingyan,Li, Lin,Yao, Shao Q.
supporting information; experimental part, p. 10939 - 10941 (2011/11/30)
Synthesis of the first self-immobilizing, fluorogenic unnatural amino acid that mimics phosphotyrosine (pTyr) is reported. By using solid-phase peptide synthesis, it was subsequently incorporated into peptide-based probes which found applications in bioim
