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Synthesis and Two‐photon Photolysis of 6‐( ortho ‐Nitroveratryl)‐Caged IP 3 in Living Cells
Author(s) -
Kantevari Srinivas,
Hoang Caroline J.,
Ogrodnik Jakob,
Egger Marcel,
Niggli Ernst,
EllisDavies Graham C. R.
Publication year - 2006
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200500345
Subject(s) - photodissociation , chemistry , quantum yield , two photon excitation microscopy , photochemistry , in vivo , laser , biophysics , fluorescence , optics , physics , biology , microbiology and biotechnology
The synthesis of a photolabile derivative of inositol‐1,4,5‐trisphosphate (IP 3 ) is described. This new caged second messenger (6‐ ortho ‐nitroveratryl)‐IP 3 (6‐NV‐IP 3 ) has an extinction coefficient of 5000 M −1 cm −1 at 350 nm, and a quantum yield of photolysis of 0.12. Therefore, 6‐NV‐IP 3 is photolyzed with UV light about three times more efficiently than the widely used P 4(5) ‐1‐(2‐nitrophenyl)ethyl‐caged IP 3 (NPE‐IP 3 ). 6‐NV‐IP 3 has a two‐photon cross‐section of about 0.035 GM at 730 nm. This absorbance is sufficiently large for effective two‐photon excitation in living cells at modest power levels. Using near‐IR light (5 mW, 710 nm, 80 MHz, pulse‐width 70 fs), we produced focal bursts of IP 3 in HeLa cells, as revealed by laser‐scanning confocal imaging of intracellular Ca 2+ concentrations. Therefore, 6‐NV‐IP 3 can be used for efficient, subcellular photorelease of IP 3 , not only in cultured cells but also, potentially, in vivo. It is in the latter situation that two‐photon photolysis should reveal its true forte.