Graduate School of Bioresources, Mie University, 1577 Kurimamachiya, Tsu, Mie, 514-8507, Japan.
Biochem Biophys Res Commun. 2018 Sep 26;504(1):190-195. doi: 10.1016/j.bbrc.2018.08.153. Epub 2018 Aug 29.
Mycena chlorophos is a species of molecular oxygen-dependent bioluminescent fungus, and its pileus gills emit bright green light. The chemical mechanisms underlying this bioluminescence phenomenon are not yet understood. An enzyme (luciferase) producing light from trans-3-hydroxyhispidin is present in M. chlorophos pileus gills. However, it is unclear whether trans-3-hydroxyhispidin is an actual bioluminescence substrate (luciferin) in the natural bioluminescence of M. chlorophos. In the present study, this question is resolved. It was clearly demonstrated that the trans-3-hydroxyhispidin analog trans-3-hydroxybisnoryangonin significantly inhibited the artificial luminescence induced by the addition of trans-3-hydroxyhispidin to living pileus gills but did not inhibit natural bioluminescence in living pileus gills. This inhibition was due to the reaction of trans-3-hydroxybisnoryangonin with luciferase for trans-3-hydroxyhispidin. Even though trans-4-aminocinnamic acid is known to inhibit natural bioluminescence in living pileus gills, in the present study, trans-4-aminocinnamic acid did not influence the artificial luminescence via trans-3-hydroxyhispidin in the presence of luciferase for trans-3-hydroxyhispidin. These inconsistencies between the natural bioluminescence and the artificial luminescence of trans-3-hydroxyhispidin indicate that trans-3-hydroxyhispidin is not an actual luciferin in natural bioluminescence. Trans-3,4-dihydroxycinnamic acid is generally known to be an intermediate in trans-3-hydroxyhispidin biosynthesis. The artificial luminescence induced by the addition of trans-3,4-dihydroxycinnamic acid to living pileus gills was not inhibited by trans-3-hydroxybisnoryangonin. Therefore, trans-3,4-dihydroxycinnamic acid does not contribute to the luminescence involving trans-3-hydroxyhispidin in living pileus gills.
绿蝇伞是一种依赖分子氧的生物发光真菌，其菌褶发出明亮的绿光。这种生物发光现象的化学机制尚不清楚。在 M. chlorophos 菌褶中存在一种酶（荧光素酶），它能将 trans-3-羟基组氨酸转化为发光物质。然而，trans-3-羟基组氨酸是否是 M. chlorophos 天然生物发光中的实际发光底物（荧光素）尚不清楚。在本研究中，这个问题得到了解决。研究清楚地表明，trans-3-羟基组氨酸类似物 trans-3-羟基双降烟碱显著抑制了向活菌褶中添加 trans-3-羟基组氨酸诱导的人工发光，但不抑制活菌褶中的天然生物发光。这种抑制作用是由于 trans-3-羟基双降烟碱与荧光素酶对 trans-3-羟基组氨酸的反应所致。尽管已知 trans-4-氨基肉桂酸会抑制活菌褶中的天然生物发光，但在本研究中，即使存在 trans-3-羟基组氨酸的荧光素酶，trans-4-氨基肉桂酸也不会影响人工发光。trans-3-羟基组氨酸的天然生物发光和人工发光之间的这些不一致表明，trans-3-羟基组氨酸不是天然生物发光中的实际荧光素。trans-3,4-二羟基肉桂酸通常被认为是 trans-3-羟基组氨酸生物合成的中间产物。向活菌褶中添加 trans-3,4-二羟基肉桂酸诱导的人工发光不会被 trans-3-羟基双降烟碱抑制。因此，trans-3,4-二羟基肉桂酸不会促进活菌褶中涉及 trans-3-羟基组氨酸的发光。
