Coelenterazine e is a synthetic derivative of coelenterazine, and is a superior substrate for Renilla luciferase. Coelenterazine e generates nearly 40% more light than native coelenterazine does while the initial light intensity of the former is more than 7 times higher than that of the latter. The emission spectrum of coelenterazine e/Renilla luciferase has two peaks centered at 418 and 475 nm, respectively.Coelenterazine e is also a good substrate for apoaequorin and, compared with coelenterazine native, the e-aequorin compelx formed from coelenterazine e has a faster luminescence rise time and shows two emission peaks at 405 and 465 nm respectively, with the ratio of the peak heights dependent on calcium concentration in the range pCa 5-7. The dual emission makes coelenterazine e/apoaequorin possible to be used for calcium detection using the ratio of the two emission intensities.
