Niwa Kazuki, Nakamura Mitsuhiro, Ohmiya Yoshihiro
Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, AIST, Japan.
FEBS Lett. 2006 Oct 2;580(22):5283-7. doi: 10.1016/j.febslet.2006.08.073. Epub 2006 Sep 11.
The chirality of the luciferin substrate is critical to the luciferin-luciferase reaction producing bioluminescence. In firefly, the biosynthetic pathway of D-luciferin is still unclear, although it can be synthesized in vitro from D-cysteine. Here, we show that the firefly produces both D- and L-luciferin, and that the amount of active D-luciferin increases gradually with maturation stage. Studies of firefly body extracts indicate the possible conversion of L-cysteine via L-luciferin into D-luciferin, suggesting that the biosynthesis is enzymatically regulated by stereoisomeric bio-inversion of L-luciferin. We conclude that the selection of chirality in living organisms is not as rigid as previously thought.
荧光素底物的手性对于产生生物发光的荧光素 - 荧光素酶反应至关重要。在萤火虫中，虽然D - 荧光素可由D - 半胱氨酸体外合成，但其生物合成途径仍不清楚。在此，我们表明萤火虫同时产生D - 和L - 荧光素，并且活性D - 荧光素的量随着成熟阶段逐渐增加。对萤火虫身体提取物的研究表明，L - 半胱氨酸可能通过L - 荧光素转化为D - 荧光素，这表明生物合成是由L - 荧光素的立体异构生物转化酶促调节的。我们得出结论，生物体中手性的选择并不像以前认为的那样严格。
