User:Matt Whelihan: Difference between revisions
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[[Image:luciferase.jpg]]'''Japanese Firefly Luciferase (''Luciola cruciata'')''' | |||
[[Image:luciferase.jpg]]''' | |||
==Luciferases== | ==Luciferases== | ||
Bioluminescence is the process by which living organisms convert chemical energy into photons of light and it is widely distributed throughout the animals, plants and fungi <ref>PMID:6358519</ref>. Species use bioluminescence as a survival tool in mating, defense and hunting. The one thing that all bioluminescent species have in common is that they all catalyze the reaction with an enzyme generically called a luciferase. All luciferases oxidize a substrate, which then decays back to the ground state while emitting a photon of light. This process is incredibly efficient with almost one photon of light produced per oxidation. While all lucifeases oxidize their substrates, the cofactors involved and reaction pathways used, vary widely <ref>PMID:775940</ref><ref>PMID:14444706</ref>. | Bioluminescence is the process by which living organisms convert chemical energy into photons of light and it is widely distributed throughout the animals, plants and fungi <ref>PMID:6358519</ref>. Species use bioluminescence as a survival tool in mating, defense and hunting. The one thing that all bioluminescent species have in common is that they all catalyze the reaction with an enzyme generically called a luciferase. All luciferases oxidize a substrate, which then decays back to the ground state while emitting a photon of light. This process is incredibly efficient with almost one photon of light produced per oxidation. While all lucifeases oxidize their substrates, the cofactors involved and reaction pathways used, vary widely <ref>PMID:775940</ref><ref>PMID:14444706</ref>. | ||
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== Catalysis == | == Catalysis == | ||
Firefly luciferases catalyze the formation of the <scene name='User:Matt_Whelihan/Complete_active_site/1'>luciferin-adenylate intermediate</scene>. A proton is then abstracted in a steriospecific manner from the C-4 carbon, presumably by an <font color='gold'>enzyme base</font> believed to be <scene name='User:Matt_Whelihan/Complete_active_site/3'>Thr343</scene>. A conformational change then occurs which allows molecular oxygen addition to the newly formed anion. As the highly reactive dioxetanone intermediate decays to the ground state, it releases a photon of light<ref>PMID:7000855</ref><ref>PMID:4813372</ref>. | Firefly luciferases catalyze the formation of the <scene name='User:Matt_Whelihan/Complete_active_site/1'>luciferin-adenylate intermediate</scene> <font color='blue'>(Blue)</font>. A proton is then abstracted in a steriospecific manner from the C-4 carbon, presumably by an <font color='gold'>enzyme base</font> believed to be <scene name='User:Matt_Whelihan/Complete_active_site/3'>Thr343</scene>. A conformational change then occurs which allows molecular oxygen addition to the newly formed anion. As the highly reactive dioxetanone intermediate decays to the ground state, it releases a photon of light<ref>PMID:7000855</ref><ref>PMID:4813372</ref>. | ||
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