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QUENCHING OF SINGLET OXYGEN BY BIOMOLECULES FROM L1210 LEUKEMIA CELLS
Author(s) -
Baker Ayse,
Kanofsky Jeffrey R.
Publication year - 1992
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1992.tb04273.x
Subject(s) - singlet oxygen , quenching (fluorescence) , chemistry , photochemistry , oxygen , photosensitizer , singlet state , phosphorescence , l1210 cells , limiting oxygen concentration , molecule , fluorescence , cytotoxicity , in vitro , excited state , organic chemistry , atomic physics , biochemistry , physics , quantum mechanics
— Singlet oxygen lifetimes for detergent‐dispersed L1210 leukemia cells in deuterium oxide buffer were measured by following the decay of 1270 nm phosphorescence. Four photosensitizers and two detergents were studied. Stern‐Volmer plots were linear over the cell concentration range studied (0–10 7 cells/mL). The singlet‐oxygen quenching constants obtained depended somewhat upon the specific combination of detergent and photosensitizer used. Extrapolation of the singlet‐oxygen lifetime data to “100%” cell concentration (1.39 ± 0.04 × 10 9 cells/mL) and correction for the contribution of the water solvent gave a singlet‐oxygen lifetime between 0.17 and 0.32 us for the L1210 leukemia cell. The theoretical contributions of various types of biological molecules within the L1210 cell to the total singlet‐oxygen quenching were calculated from their concentrations and their quenching constants. These calculations suggest that proteins will quench most of the singlet‐oxygen. Only about 7% of the singlet‐oxygen is quenched by water.