Fig. 3
From: Regulation of myocardial contraction as revealed by intracellular Ca2+ measurements using aequorin
Modified from Fig. 1 of [70] with permission.
Schematic illustration showing the Ca2+-dependent light generation by aequorin. Apo-aequorin is converted to the active form of aequorin when reconstituted by a luminophore coelenterazine in the presence of O2. Coelenterazine is oxidized by binding with three Ca2+ molecules to the respective EF-hands in aequorin; the subsequent conformational change of the protein in association with the release of CO2 produces the singlet-excited coelenteramide that emits blue light (hv ~ 470 nm). The portion of coelenterazine where intramolecular changes occur is indicated in green.