Selenium cannot substitute for sulfur in cell density-independent bioluminescence in Vibrio fischeri.
It has been proposed that selenium, an element chemically similar to sulfur, can participate in some of the same biological pathways as sulfur, although only a few studies have been confirmed this. In this study, we investigated the relationship between selenium and sulfur-dependent luminescence in Vibrio fischeri. The luminescence of V. fischeri was induced by the addition of sulfur-containing compounds such as Na₂SO₄ and L-cystine, and their luminescence was suppressed, in a dose-dependent manner, by the addition of the selenium-containing compounds Na₂SeO₄ and L-selenocystine. Since the viability of V. fischeri was not affected by the addition of low concentration of selenium-containing compounds, the decrease in luminescence intensity cannot be explained by cell death. Kinetic analysis performed using Lineweaver-Burk plots demonstrate that Na₂SeO₄ and L-selenocystine act as competitive suppressors in inorganic sulfur (Na₂SeO₄)-dependent luminescence. In contrast, these selenium-containing compounds act as uncompetitive suppressors in organic sulfur (L-cystine)-dependent luminescence.
Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
Yosuke
Y
Tabei
Mariko
M
Era
Akane
A
Ogawa
Junko
J
Ninomiya
Tomonori
T
Kawano
Hiroshi
H
Morita
D048908:Aliivibrio fischeri / Q000378:metabolism*; D049449:Luminescence; D008164:Luminescent Proteins / Q000378:metabolism*; D012643:Selenium / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*
D008164:Luminescent Proteins; D013455:Sulfur; D012643:Selenium