[7-(Dialkylamino)coumarin-4-yl]methyl-Caged Compounds as Ultrafast and Effective Long-Wavelength Phototriggers of 8-Bromo-Substituted Cyclic Nucleotides.
[7-(Dimethylamino)coumarin-4-yl]methyl (DMACM) and [7-(diethylamino)coumarin-4-yl]methyl (DEACM) esters of 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) and 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) are described as novel caged compounds for 8-bromo-substituted cyclic nucleotides. Synthesis is accomplished by treatment of the free acids of the cyclic nucleotides with the corresponding 7(dialkylamino)-substituted 4(diazomethyl)coumarins. Irradiation of the DMACM- and DEACM-caged cyclic nucleotides with UV light stimulates the release of the cyclic nucleotides within roughly a nanosecond. The new caged compounds are resistant to hydrolysis in aqueous buffers and exhibit long-wavelength absorption properties with maxima at 400 nm, high extinction coefficients, and high quantum yields (0.15-0.31). Their favorable properties render these compounds the most efficient and rapid phototriggers of 8-bromo-substituted cyclic nucleotides known. The usefulness of the compounds for physiological studies under nondamaging light conditions was examined in HEK293 cells expressing the alpha subunit of the cyclic-nucleotide-gated (CNG) channel of cone photoreceptors (CNGA3) and of olfactory neurons (CNGA2) by using confocal laser scanning microscopy and the patch clamp technique.
Forschungsinstitut für Molekulare Pharmakologie Robert-Rössle-Strasse 10, 13125 Berlin, Germany. hagen@fmp-berlin.de
Volker
V
Hagen
Stephan
S
Frings
Burkhard
B
Wiesner
Siegrun
S
Helm
U Benjamin
UB
Kaupp
Jürgen
J
Bendig
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000737:chemistry*; D000818:Animals; D002460:Cell Line; D003374:Coumarins / Q000138:chemical synthesis / Q000737:chemistry*; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000737:chemistry*; D054815:Cyclic Nucleotide-Gated Cation Channels; D006801:Humans; D007473:Ion Channels / Q000737:chemistry / Q000378:metabolism; D007536:Isomerism; D018613:Microscopy, Confocal; D018034:Olfactory Receptor Neurons / Q000737:chemistry; D018408:Patch-Clamp Techniques; D010782:Photolysis; D051381:Rats; D017949:Retinal Cone Photoreceptor Cells / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D003374:Coumarins; D054815:Cyclic Nucleotide-Gated Cation Channels; D007473:Ion Channels; D015124:8-Bromo Cyclic Adenosine Monophosphate; C016276:8-bromocyclic GMP; D006152:Cyclic GMP