What is the excitation emission of wild type GFP?

Excitation and Emission of Wild Type Green Fluorescent Protein (GFP)

The Green Fluorescent Protein (GFP), originally discovered in the jellyfish Aequorea victoria, has become a fundamental marker in molecular biology, biotechnology, and biochemistry. Its unique ability to fluoresce green light when exposed to ultraviolet light has made it an invaluable tool for visualizing and tracking gene expression and protein localization in live cells and organisms.

Excitation and Emission Characteristics

The wild type GFP exhibits specific excitation and emission spectra that are characteristic of its unique chromophore. The excitation peak of wild type GFP is at approximately 395 nm (major peak) with a secondary, less pronounced peak at around 475 nm. Upon excitation, GFP emits fluorescence with a peak at 509 nm, producing its distinctive green color.

Mechanism of Fluorescence

The fluorescence of GFP is attributed to its chromophore, which is formed by a post-translational modification of the protein's amino acids serine, tyrosine, and glycine at positions 65-67. This process, which occurs spontaneously without the need for additional enzymes or cofactors, involves cyclization and oxidation to form the fluorescent chromophore.

Applications of GFP

• Gene expression and regulation studies
• Protein localization and tracking within cells
• Reporter gene in genetic engineering and molecular biology research
• Bioluminescence imaging in medical and biological research

In summary, the wild type GFP's unique excitation and emission properties have made it a cornerstone in scientific research, enabling detailed studies of cellular processes in real time. Its discovery and subsequent modifications have led to a variety of GFP derivatives with altered fluorescence characteristics, further expanding its utility in research.