Abstracts

Currently, only two metabolic pathways are known for bioluminescent mechanisms: one involving the lipid synthesis pathway in bacteria and the other involving the metabolization of caffeic acid by fungi. Within the fungal bioluminescence pathway, four enzymes play crucial roles: hispidin synthase (HispS), the polyketide synthases that catalysis the several carbon addition reaction on caffeic acid substrate to produce hispidin; hispidin-3-hydroxylase (H3H), enzyme that catalyzes the mono-oxygenation of hispidin at C3 of α-pyrone ring, producing the fungal luciferin (3-hydroxyhispidin); luciferase (Luz) that catalyze the oxidation of luciferin by insertion of the molecular oxygen to produce the high-energy intermediate (HEI) endoperoxide. After the decomposition of the HEI and the decay to ground state of excited oxyluciferin, the last enzyme is caffeylpyruvate hydrolase (CPH), that catalyzes the hydrolytic cleavage of oxyluciferin. Our laboratory has investigated CPH and confirmed its catalytic activity in recycling the system, producing caffeic acid and pyruvic acid from oxiluciferin. While studying extracts of total proteins from Neonothopanus gardneri mycelium, we identified CPH's catalytic activity. However, when conducting similar tests with bioluminescent mushrooms from the Atlantic forest, Gerronema viridilucens and Mycena lucentipes, we observed that oxyluciferin consumption resulted in another compound with a red-shifted absorbance spectrum by possible enzymatic reaction. Therefore, this study aims to present preliminary results on a potential second route of oxyluciferin consumption in addition to the known route for recycling bioluminescent systems, which may suggest a new role for this molecule.