Renilla luciferase catalyses coelenterazine oxidation by oxygen to produce light, and is used as a reporter enzyme in luminescence-based assays. Coelenterazine native is the natural substrate for Renilla luciferase. In addition, over a dozen coelenterazine analogues have been synthesised. These coelenterazine analogues can function as substrates for Renilla luciferase with differences in cell membrane permeability, quantum efficiency, and emission wavelength. Emission wavelength is an important consideration when Renilla luciferase is used in combination with a fluorescent protein such as GFP for bioluminescent resonance energy transfer (BRET), an important application for the studies of protein-protein interactions.
Coelenterazine and its analogues also are substrates for apoaequorin. Aequorins can be used for bioluminescent detection of calcium with high sensitivity and dynamics. Compared with fluorescent calcium indicators, the aequorin complex has several advantages in detecting calcium. One major advantage is that the aequorin complex can detect a broad range of calcium concentrations, from ~0,1 mm to >100 mm. Another advantage of aequorin-based calcium assays is that it is possible to monitor calcium concentration in cells over hours to days. Coelenterazine e has two emission peaks at 405 nm and 465 nm, with the ratio of peak heights dependent on calcium concentration, permitting ratiometric calcium measurements using aequorin.
Biotium offers high purity native coelenterazine and a number of coelenterazine analogues. The coelenterazine sampler kit contains 25 ug each of native coelenterazine and coelenterazine analogs cp, f, fcp, h, hcp, i, ip, and n. Aquaphile™ coelenterazines are specially formulated to be water soluble for in vivo use. Biotium also offers Renilla luciferase assay kits for detection of Renilla luciferase reporter gene expression.