Green Fluorescent Protein(GFP) - DnaTube.com - Scientific Video and Animation Site

Green Fluorescent Protein(GFP)

Click Here to skip this ad below and watch video

11998 views | 10m 3s

Green florescent protein (GFP) has revolutionized research in medicine and biology, enabling scientist to get a visual fix on how organs function on the spread of disease and the response of infected cells to treatment, In 2008 Nobel Chemsitry prize was announced to Osamu Shimomura of Japan and American duo Martin chalfie and Roger Tsien for deriving Florescent protein from a jellyfish Aequorea Victoria. The GFP is composed of 238 amino acids; it is isolated from jellyfish Aequorea Victoria that fluoresces green when exposed to blue light.It was discovered GFP has a typical beta barrel structure, consisting of one β-sheet with a alpha helix containing the fluorophore running through the center, while the tightly packed barrel shell protects the flurophore from quenching by the surrounding microenviornment,the inward facing side chains of the barrel induce specific cyclization reactions on the tripeptide Ser65-Tyr66-Gly67 that lead to fluorophore formation. This occurs in a series of discrete steps with distinct excitation and emission properties. GFP has functioned has a guiding star for bichemist, biologist and medical scientist, The gene to make GFP is inserted into the DNA of lab animals, bacteria or other cells, where it is switched on by other genes, the glow becomes apparent under ultraviolet light, The telltale protein gives researchers an instant way of monitoring process that were previously invisible. By targeting nerve cells in Alzheimer’s disease person scientist can follow the, destruction caused by disease, Tumour progression can be followed by adding GFP to cancer cells, By adding GFP to a growing mouse embryo, they can see how the pancreas generates insulin-producing beta cells. Today GFP is a standard tool for thousands of researchers all over the world GFP derivatives Due to the potential for widespread usage and the evolving needs of researchers, many different mutants of GFP have been engineered. The first major improvement was a single point mutation (S65T) reported in 1995 in Nature by Roger Tsien This mutation dramatically improved the spectral characteristics of GFP, resulting in increased fluorescence, photostability and a shift of the major excitation peak to 488nm with the peak emission kept at 509 nm. This matched the spectral characteristics of commonly available FITC filter sets, increasing the practicality of use by the general researcher. The addition of the 37 °C folding efficiency (F64L) point mutant to this scaffold yielded enhanced GFP (EGFP). EGFP has an extinction coefficient (denoted ε), also known as its optical cross section of 9.13×10−21 m²/molecule, also quoted as 55,000 M−1cm−1. The quantum yield (QY) of EGFP is 0.60. The relative brightness, expressed as ε•QY, is 33,000 M−1cm−1. Superfolder GFP, a series of mutations that allow GFP to rapidly fold and mature even when fused to poorly folding peptides, was reported in 2006. (less)

Channels: Genetics Molecular Genetics
Tags: Green Fluorescent Protein gfp