12th International Symposium on Bioluminescence & Chemiluminescence

Symposium abstracts:

The structural determinants of bioluminescence colors in railroad worm and other pH-insensitive luciferases

Viviani, Vadim R.¹, Uchida, A.,² Ohmiya, Y.²

1. Dept. Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA

Email: viviani@fas.harvard.edu.
2. Cell Dynamics Research Group Division of Human Life Technology, Osaka National Research Institute, Osaka, Japan

Previously we found that the region before residue 344 contains the main determinants of bioluminescence colors in Phrixotrix railroad worms and that R215 and T226 were important residues for green light emission in pH-insensitive luciferases (click beetle and railroad worms). Now, the construction of new chimeric luciferases using the red light emitting luciferase (PxRE; l _max = 623 nm) and the green light emitting luciferase (PxGR; l _max =548 nm) of Phrixotrix railroad worms, shows that the region between residues 220 and 344 is the main determinant of bioluminescence colors in these luciferases. However, the region before residue 220 has also a considerable influence on the spectrum. We found that R215 is not an essential residue for green light emission in all beetle luciferases, as previously thought. Through the construction of double mutants, we found that R215 and T226 act independently on the determination of bioluminescence spectra in pH-insensitive luciferases, resulting in very red-shifted emitting luciferases (l _max = 595 nm). We have also identified other conserved residues affecting the bioluminescence spectra in pH-insensitive luciferases.

---

This is a preprint of an article accepted for publication in Luminescence: Copyright 2001 John
Wiley & Sons, Ltd (Wiley website)