Inhibitory effect of lipoic acid on firefly luciferase bioluminescence.
Lipoic acid was found to inhibit the firefly luciferin-luciferase reaction. The inhibition is competitive and is the strongest known (Ki = 0.026 +/- 0.013 microM) compared with other reported inhibitors. Considering the structure-activity correlations, the mechanism of inhibition may originate from the sulfur atom and carboxyl moiety of lipoic acid giving it structural specificity. Subsequent addition of lipoic acid and nitric oxide accelerated the inhibition in vitro, suggesting that lipoic acid may have a functional role in regulating firefly bioluminescence.
Niwa
Kazuki
K
Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, Midorigaoka, Ikeda, Osaka 563-8577, Japan.
Ohmiya
Yoshihiro
Y
D000818:Animals; D001517:Coleoptera / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry; D049454:Firefly Luciferin / Q000037:antagonists & inhibitors*; D008156:Luciferases / Q000037:antagonists & inhibitors*; D008163:Luminescent Measurements; D013329:Structure-Activity Relationship; D008063:Thioctic Acid / Q000737:chemistry*
D004791:Enzyme Inhibitors; D049454:Firefly Luciferin; D008063:Thioctic Acid; D008156:Luciferases