A new mechanism that involves dissociative electron transfer in the energy transducing step is set forward for bacterial luciferase catalyzed light emission. The proposal involves (1) dissociation of the 4a-hydroperoxyflavin to a flavin radical and •O2-, accounting for 570 and 620nm absorption, (2) •O2- addition to the aldehyde carbonyl to form a peroxyl radical, (3) abstraction of H from an enzyme thiol group to form RCH(OOH)OH, (4) thiyl radical abstraction of the H on C in RCH(OOH)OH, a step which can show a kH kD of ca. 4, and (5) dissociative electron- transfer, a highly exothermic step that leads to a protonated flavin excited state, a carboxylic acid and water.
|Number of pages||9|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - 29 Jan 1980|