New optical probes for cell physiology

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Séminaire des Départements de Biologie et de Chimie de l’ENS 


Mardi 4 avril 2017 


Salle L357 / L359, 

24, rue Lhomond 

75005 Paris 


Graham Ellis-Davies 

Department of Neurosciences, Icahn School of Medicine at Mount Sinai (New York) 


New optical probes for cell physiology 


Photochemical protecting groups were developed for synthetic organic chemistry in the 1960s. When covalently linked to the many small organic biomolecules (e.g. cAMP, ATP, IP3, glutamate, GABA, etc.) that are central to cell function, these optical probes are called caged compounds. Two fundamentally different chromophores have been widely used for the photoregluation of such systems, namely nitroaromatic and coumarin platforms. My presentation will be concerned with our recent studies in these two areas. 


First, on my last visit to the ENS in 2014 I described our development of a new blue light absorbing photochemical group, based upon the 7-diethylaminocoumarin (DEAC) chromophore, which we call DEAC450. Unfortunately, like many other caged GABA probes, DEAC450-GABA is highly antagonistic towards GABA-A receptors. I will describe the development a new technology, which we call “cloaked caged compounds”, that removes this undesirable side effect of caged neurotransmitters. 


Secondly, I will also describe our recent work on a blue light absorbing nitroaromatic chromophore which we call BIST (bisstyrylthiophene) that has a large 2-photon absorption cross section (350-800 GM). Many groups have attempted to develop such a photochemical protecting group. In 2016, we introduced a caged calcium probe based upon BIST (J. Am. Chem. Soc. (2016) 138, 3687−3693 ). I will present new work describing the scope and limitations of the BIST platform.


Salle L357 / L359,  24, rue Lhomond, 75005 Paris 

Mardi 4 Avril 2017 10:30
Séminaire Thématique
Unité de rattachement: 
UMR 8640