In beetles, luciferase enzymes catalyse the conversion of chemical energy into light through bioluminescence. The principles of this process have become a fundamental biotechnological tool that revolutionized biological research. Different beetle species can emit different colours of light, despite using the same substrate and highly homologous luciferases. The chemical reasons for these different colours are hotly debated yet remain unresolved. This Review summarizes the structural, biochemical and spectrochemical data on beetle bioluminescence reported over the past three decades. We identify the factors that govern what colour is emitted by wild-type and mutant luciferases. This topic is controversial, but, in general, we note that green emission requires cationic residues in a specific position near the benzothiazole fragment of the emitting molecule, oxyluciferin. The commonly emitted green–yellow light can be readily changed to red by introducing a variety of individual and multiple mutations. However, complete switching of the emitted light from red to green has not been accomplished and the synergistic effects of combined mutations remain unexplored. The minor colour shifts produced by most known mutations could be important in establishing a ‘mutational catalogue’ to fine-tune emission of beetle luciferases, thereby expanding the scope of their applications.

在甲虫中，荧光素酶通过生物发光催化化学能转化为光能。这一过程的原理已成为彻底改变生物学研究的基本生物技术工具。尽管使用相同的底物和高度同源的荧光素酶，但不同的甲虫物种可以发出不同颜色的光。这些不同颜色的化学原因引起了激烈的争论，但仍未得到解决。本综述总结了过去三十年报道的甲虫生物发光的结构、生化和光谱化学数据。我们确定了控制野生型和突变型荧光素酶发出什么颜色的因素。这个话题是有争议的，但总的来说，我们注意到绿色发光需要在发光分子 oxyluciferin 的苯并噻唑片段附近的特定位置存在阳离子残基。通过引入各种单个和多个突变，可以很容易地将通常发出的绿-黄光变为红色。然而，发射光从红色到绿色的完全切换尚未完成，组合突变的协同效应仍未得到探索。大多数已知突变产生的微小颜色变化对于建立“突变目录”以微调甲虫荧光素酶的发射可能很重要，从而扩大其应用范围。发射光从红色到绿色的完全切换尚未完成，组合突变的协同效应仍未得到探索。大多数已知突变产生的微小颜色变化对于建立“突变目录”以微调甲虫荧光素酶的发射可能很重要，从而扩大其应用范围。发射光从红色到绿色的完全切换尚未完成，组合突变的协同效应仍未得到探索。大多数已知突变产生的微小颜色变化对于建立“突变目录”以微调甲虫荧光素酶的发射可能很重要，从而扩大其应用范围。