title: Coumarin-caged glycine that can be photolyzed within 3 microseconds by visible light.
abstract: The synthesis and characterization of a new photolabile precursor of glycine (coumarin-caged glycine) are reported. The new compound is suitable for rapid chemical kinetic investigations of the membrane-bound neurotransmitter receptor activated by glycine. Unlike previously used caging groups for glycine, this precursor can be photolyzed rapidly and efficiently in the visible wavelength region. This allows the use of a relatively inexpensive light source. The alpha-carboxyl group of glycine was covalently coupled to the 7-(diethylamino)coumarin (DECM) caging group. The caged compound has a major absorption band with a maximum at 390 nm (epsilon390 = 13,900 M-1 cm-1). Photolysis was performed at wavelengths of >or=400 nm (epsilon400 = 12,400 M-1 cm-1). Under physiological conditions, DECM-caged glycine is water soluble and stable. In the visible wavelength region, it photolyzes rapidly to release glycine with a half-life of approximately 2.5 micrometers and a quantum yield of 0.12 +/- 0.01. The experimental results demonstrated that neither DECM-caged glycine nor its byproduct inhibits or activates human alpha1 glycine receptors expressed on the surface of HEK 293 cells.
authors.affiliation: Department of Molecular Biology and Genetics, 216 Biotechnology Building, Cornell University, Ithaca, New York 14853-1301, USA.
authors.forename: Vishakha R
authors.initials: VR
authors.lastname: Shembekar
authors.forename: Yongli
authors.initials: Y
authors.lastname: Chen
authors.forename: Barry K
authors.initials: BK
authors.lastname: Carpenter
authors.forename: George P
authors.initials: GP
authors.lastname: Hess
mesh_terms: D002460:Cell Line; D003374:Coumarins / Q000138:chemical synthesis* / Q000378:metabolism; D005998:Glycine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000378:metabolism; D006801:Humans; D007834:Lasers; D010782:Photolysis; D017981:Receptors, Neurotransmitter / Q000737:chemistry / Q000378:metabolism
chemical_list: C519895:7-(N,N-diethylamino)-4-(hydroxymethyl)coumarin methyl-N-tert-Boc-glycine; D003374:Coumarins; D017981:Receptors, Neurotransmitter; D005998:Glycine