CH391L/S12/Fluorescent Proteins

Green Fluorescent Protein (GFP)

History

GFP was first discovered by Osamu Shimomura in Aequorea jellyfish as a companion protein to the aequorin responsible for the blue glow of the organism.[1][2] Shimomura and his group further characterized and identified the peak luminescence of GFP as similar to that of Aequorea tissue, both of which differed from the peak of the aequorin protein significantly, indicating that GFP altered the color of the aequorin from its natural blue to the green expressed by the organism. They showed that the mechanism for this was transfer of energy from the aequorin to GFP in the presence of a cation[3] The crucial breakthrough came when Douglas Prasher et al cloned the gene and identified its amino acid and DNA sequence.[4] Further characterization showed that expression of the gene led to luminescence in other organism, providing the key inference that all of the information necessary for post-translational synthesis of the chromophore was in the gene itself, and no jellyfish-specific enzymes were needed for production of functional GFP.

Structure

GFP consists of a single β-sheet with alpha helices containing the covalently bonded chromophore 4-(p-hydroxybenzylidene)imidazolidin-5-one (HBI) running through the center.

GFP molecules drawn in cartoon style, one fully and one with the side of the beta barrel cut away to reveal the chromophore

References

1. SHIMOMURA O, JOHNSON FH, and SAIGA Y. Extraction, purification and properties of aequorin, a bioluminescent protein from the luminous hydromedusan, Aequorea. J Cell Comp Physiol. 1962 Jun;59:223-39. DOI:10.1002/jcp.1030590302 |
2. Tsien RY. The green fluorescent protein. Annu Rev Biochem. 1998;67:509-44. DOI:10.1146/annurev.biochem.67.1.509 |
3. Morise H, Shimomura O, Johnson FH, and Winant J. Intermolecular energy transfer in the bioluminescent system of Aequorea. Biochemistry. 1974 Jun 4;13(12):2656-62. DOI:10.1021/bi00709a028 |
4. Prasher DC, Eckenrode VK, Ward WW, Prendergast FG, and Cormier MJ. Primary structure of the Aequorea victoria green-fluorescent protein. Gene. 1992 Feb 15;111(2):229-33. DOI:10.1016/0378-1119(92)90691-h |