Apoaequorin is a protein known for its unique properties and its role in biological systems. This article explores its characteristics, natural origins, and methods for commercial production, providing a comprehensive understanding of what apoaequorin is and how it is obtained.
What is Apoaequorin?
Apoaequorin is a protein known for its ability to interact with calcium ions. It functions as a calcium-binding protein, attaching to calcium within a cellular environment. This interaction is central to its natural role in bioluminescence, a process where living organisms produce light.
Composed of 196 amino acids, apoaequorin is the inactive form of a larger complex called aequorin. When apoaequorin binds with calcium, it transforms, and in the presence of coelenterazine, emits blue light. This light-producing reaction has made aequorin a valuable tool in scientific research for monitoring calcium levels inside cells.
Natural Source
Apoaequorin was originally discovered and isolated from Aequorea victoria, also known as the crystal jelly. This bioluminescent hydrozoan is commonly found off the west coast of North America, particularly in the Pacific Ocean. The discovery of apoaequorin and its related protein, Green Fluorescent Protein (GFP), in this jellyfish was a notable scientific finding.
Research into the bioluminescence of Aequorea victoria began in the early 1960s, led by scientist Osamu Shimomura. This work involved collecting tens of thousands of jellyfish from locations such as Friday Harbor, Washington. Researchers observed that extracts from these jellyfish produced light when exposed to seawater containing calcium. While apoaequorin generates blue light upon calcium binding, the jellyfish emits green light because GFP absorbs this blue light and re-emits it as green light.
Commercial Production
For commercial purposes, apoaequorin is not harvested directly from jellyfish due to the impracticality and scalability challenges of this method. Instead, it is produced through recombinant DNA technology, also known as genetic engineering. This method involves inserting the gene for apoaequorin into an easily cultured organism, such as E. coli bacteria or yeast. These microorganisms then act as biological factories, producing large quantities of the protein.
Recombinant technology offers several advantages over natural extraction. It provides a more sustainable and ethical source for the protein, eliminating the need to harvest large numbers of jellyfish. This method also allows for greater control over the purity and consistency of the manufactured apoaequorin. The resulting recombinant apoaequorin is chemically identical to the protein found naturally in the jellyfish, despite being produced in a different host organism. After production, the protein is purified, concentrated, and dried, often formulated into a pill for dietary supplements.