Aequorin

Aequorin 1
Aequorin ribbon diagram from PDB 1ej3 with prosthetic group coelenterazine in blue
Identifiers
Organism	Aequorea victoria (Jellyfish)
Symbol	N/A
UniProt	P07164
Other data
EC number	1.13.12.5

Aequorin is a calcium-activated photoprotein isolated from the hydrozoan Aequorea victoria. Though the bioluminescence was studied decades before, the protein was originally isolated from the animal by Osamu Shimomura. In the animals, the protein occurs together with the Green fluorescent protein to produce green light by resonant energy transfer, while aequorin by itself generates blue light.

Discussions of "jellyfish DNA" to make "glowing" animals often refer to transgenic animals which express the Green fluorescent protein, not aequorin, although both originally derived from the same animal.

Work on aequorin began with E. Newton Harvey in 1921. Though Harvey was unable to demonstrate a classical luciferase-luciferin reaction, he showed that water could produce light from dried and that light could be produced even in the absence of oxygen. Later, Osamu Shimomura began work into the bioluminescence of Aequorea in 1961. This involved tedious harvesting of tens of thousands of jellyfish from the docks in Friday Harbor, Washington. It was determined that light could be produced from extracts with seawater, and more specifically, with calcium. It was also noted during the extraction the animal creates green light due to the presence of the green fluorescent protein, which changes the native blue light of aequorin to green.