Difference between revisions of "20.109(S09): Transfection (Day5)"
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Let's start by learning more about luciferase, which is an enzyme that oxidizes its substrate, luciferin. The product, oxyluciferin, emits light in the blue range of the visible spectrum, 440-479 nm. The oxidation reaction is fundamentally different from another light emitting reaction that you are now intimately familiar with, fluorescence. During fluorescence, absorbed light is re-emitted by the excited fluor as light of a longer wavelength (this is called a Stokes shift); in the case of GFP, absorbed blue light is emitted as green light, ~ 505 nm. Interestingly our luciferase source, ''Renilla reformis'', has both a luciferase-luciferin pair as well as GFP. Consequently the oxidation reaction can lead to oxyluciferin luminescence and then to fluorescence, through energy transfer to GFP, giving the soft corals a blue-green glow. | Let's start by learning more about luciferase, which is an enzyme that oxidizes its substrate, luciferin. The product, oxyluciferin, emits light in the blue range of the visible spectrum, 440-479 nm. The oxidation reaction is fundamentally different from another light emitting reaction that you are now intimately familiar with, fluorescence. During fluorescence, absorbed light is re-emitted by the excited fluor as light of a longer wavelength (this is called a Stokes shift); in the case of GFP, absorbed blue light is emitted as green light, ~ 505 nm. Interestingly our luciferase source, ''Renilla reformis'', has both a luciferase-luciferin pair as well as GFP. Consequently the oxidation reaction can lead to oxyluciferin luminescence and then to fluorescence, through energy transfer to GFP, giving the soft corals a blue-green glow. | ||
− | Luciferin-luciferase pairs are widely used in nature for courtship, camouflage or baiting. Fireflies (also known as lightning bugs or more technically ''Photinus pyralis'') use an ATP-requiring luciferin-luciferase pair and emit species-specific patterns of light as part of their mating ritual. Bioluminescent bacteria (such as ''Vibrio harveyi'') can be found in symbiotic relationships with marine organisms. The fish give such bacteria a suitable home and in return the bacteria emit light to give the fish | + | Luciferin-luciferase pairs are widely used in nature for courtship, camouflage or baiting. Fireflies (also known as lightning bugs or more technically ''Photinus pyralis'') use an ATP-requiring luciferin-luciferase pair and emit species-specific patterns of light as part of their mating ritual. Bioluminescent bacteria (such as ''Vibrio harveyi'') can be found in symbiotic relationships with marine organisms. The fish give such bacteria a suitable home and in return the bacteria emit light to give the fish |