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Green and Red Fluorescent Proteins Paper Models

Green Fluorescent Protein (GFP)

GFP is found in a jellyfish that lives in the cold waters of the north Pacific. The jellyfish contains a bioluminescent protein–aequorin–that emits blue light. GFP converts it to green light which we see when the jellyfish lights up. The GFP shown here and used as a base for paper model is from PDB structure 1ema. To learn more about GFPs read the Molecule of the Month.

GFP-like Proteins

After GFP was discovered, scientists looked to nature and found fluorescent proteins producing light of different colors in different organisms. The one you can model using the template below is dsRED (based on PDB structure 1g7k) which was discovered in a species of coral. As the name implies, it emits red light. This protein naturally exists as a complex of four protein chains. Read the Molecule of the Month on GFP-like Proteins to learn more.

The 3D Structure

The fluorescent proteins assume similar 3D shape. The chain forms a cylindrical can, with one portion of the strand threading straight through the middle. The specific part responsible for fluorescence, called the chromophore, is shielded in the middle of the can. Jostling water molecules would normally rob the chromophore of its energy once it absorbs a photon. But it is protected inside the protein, releasing the energy instead as a slightly less energetic photon of light. The chromophore forms spontaneously from three amino acids in the protein chain: a glycine, a tyrosine and a threonine (or serine).