Dehydroluciferyl-AMP is the main intermediate in the luciferin dependent synthesis of Ap4A catalyzed by firefly luciferase

It was previously assumed that E.LH2-AMP was the intermediate complex in the synthesis of Ap(4)A catalyzed by firefly luciferase (EC 1.13.12.7), when luciferin (LH2) was used as cofactor. However, here we show that LH2 is partly transformed, shortly after the onset of the luciferase reaction, to dehydroluciferin (L) with formation of an E.L-AMP complex which is the main intermediate for the synthesis of Ap(4)A. Formation of three more derivatives of LH2 were also observed, related to the production of light by the enzyme, CoA, a known stimulator of light production, inhibits the synthesis of Ap(4)A by reacting with the E.L-AMP complex and yielding L-CoA. (C) 1998 Federation of European Biochemical Societies.