Sandbox Reserved 993: Difference between revisions
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[[Image:Luciferin_Mechanism.jpg|400px|thumb|right|Schematic representation of the ''Photinus pyralis'' lucerifase reaction.<ref name=Branchini1998 /> | [[Image:Luciferin_Mechanism.jpg|400px|thumb|right|Schematic representation of the ''Photinus pyralis'' lucerifase reaction.<ref name=Branchini1998 /> | ||
Step 1: ''Photinus pyralis'' luciferase catalyzes the production of luciferyl-AMP from luciferin and ATP. An inorganic pyrophosphate is released in this reaction. | Step 1: ''Photinus pyralis'' luciferase catalyzes the production of luciferyl-AMP from luciferin and ATP. An inorganic pyrophosphate is released in this reaction. | ||
Step 2: ''Photinus pyralis'' luciferase then converts luciferyl-AMP and O<sub>2</sub> into oxyluciferin and CO<sub>2</sub>.<ref name=White1980 /><ref name=Thorne2012>Thorne, N., Shen, M., Lea, W. A., Simeonov, A., Lovell, S., Auld, D. S. and Inglese, J. (2012) "Firefly luciferase in chemical biology: A compendium of inhibitor, mechanistic evaluation of chemotypes, and suggested use as a reporter", Chem. Biol. 19(8): 1060-1072. doi:http://dx.doi.org/10.1016%2Fj.chembiol.2012.07.015</ref>]] | Step 2: ''Photinus pyralis'' luciferase then converts luciferyl-AMP and O<sub>2</sub> into oxyluciferin* and CO<sub>2</sub>.<ref name=White1980 /><ref name=Thorne2012>Thorne, N., Shen, M., Lea, W. A., Simeonov, A., Lovell, S., Auld, D. S. and Inglese, J. (2012) "Firefly luciferase in chemical biology: A compendium of inhibitor, mechanistic evaluation of chemotypes, and suggested use as a reporter", Chem. Biol. 19(8): 1060-1072. doi:http://dx.doi.org/10.1016%2Fj.chembiol.2012.07.015</ref> When the electrons on the oxygen of oxyluciferin* relax from their excited state, light is emitted.]] | ||
The active site environment influences the wavelength of the light emitted. Single amino acid changes within the active site of ''Photinus pyralis'' luciferase can shift the luminescence from yellow-green to red. Modifying the position of the Ser314-Leu319 loop near the active site can alter bioluminescence color. When assayed under acidic conditions, all spectra underwent a red shift, while basic conditions caused a blue shift. These experiments were done using ''E. coli'' as the host organism indicating that the internal pH of the cell was close to the external pH. These findings suggest a possible use of bioluminescence in pH monitoring, biosensing, tissue and animal imaging.<ref name=Shapiro2005 /> | The active site environment influences the wavelength of the light emitted. Single amino acid changes within the active site of ''Photinus pyralis'' luciferase can shift the luminescence from yellow-green to red. Modifying the position of the Ser314-Leu319 loop near the active site can alter bioluminescence color. When assayed under acidic conditions, all spectra underwent a red shift, while basic conditions caused a blue shift. These experiments were done using ''E. coli'' as the host organism indicating that the internal pH of the cell was close to the external pH. These findings suggest a possible use of bioluminescence in pH monitoring, biosensing, tissue and animal imaging.<ref name=Shapiro2005 /> | ||