Why is GFP the best?

SO WHY IS GFP THE BEST?

• Well, GFPs are these awesome green colored proteins...

      And...

• They have been successfully engaged in virtually EVERY biological field, from microbiology to human physiology.

• These ubiquitous markers are extremely useful as reporters for gene expressions in cultured cells, excised tissues, and whole animals.

• In live cells, GFPs are mostly used to track the localization and dynamics of proteins, organelles, and other cellular compartments.

• They can also be used to assess protein-protein interactions through the use of "resonance energy transfer techniques (FRET )." 

• The application of GFPs consists of fusing the gene for the cDNA of the target gene to that of a GFP followed by transferring the resulting recombinant vector into a host cell or whole organism. 

• "Light is produced by the bioluminescent jellyfish Aequorea victoria when calcium binds to the photoprotein aequorin. This jellyfish produces green lights. This light is the result of a second protein in A. victoria that derives its excitation energy from aequorin, the green fluorescent protein." (http://pubs.acs.org/doi/pdf/10.1021/bi00056a003)

• "Purified GFP, a protein of 238 amino acids, absorbs blue light (maximally at 395 nm with a minor peak at 470 nm) and emits green light (peak emission at 509 nm with a shoulder at 540 nm)" (http://pubs.acs.org/doi/pdf/10.1021/bi00056a003)

• It provides an excellent means for monitoring gene expression and protein localization in living cells. 

• Because it does not appear to interfere with cell growth and function, GFPs are also a convenient indicator of transformation and one that  allow normal cells to be separated with fluorescence-activated cell. 

• GFP can be used as a vital marker so that cell growth and movement can be followed, especially in animals that are essentially transparent like C. elegans and zebra fish. 

• The relatively small size of the protein my facilitate its diffusion throughout the cytoplasm of extensively branched cells like neurons and glia. 

http://zeiss-campus.magnet.fsu.edu/articles/probes/fpconsiderations.html

Pymol; protein data bank 1S6Z

Pymol; protein data bank 1S6Z 

Pymol; protein data bank 1S6Z

• GFP has jumped from being insignificant to becoming one of the most widely studied and used proteins in biochemistry and cell biology.

• It is very fascinating and amazing to observe GFP's ability to emit an internal flurophore

• GFP has a high resolution structure that helps to understand the relation between protein structure and spectroscopic function.

• GFP is used extensively in observing protein interaction and gene expression in intact cells and organisms

• GFP are also used to find out the behaviors of cancerous cells, which is a huge contribution to the field of oncology in the discovery of new type of cancers.

I'm sure you're convinced by now that GFPs are the best :)

References

http://zeiss-campus.magnet.fsu.edu/articles/probes/fpconsiderations.html

http://www.ncbi.nlm.nih.gov/pubmed/9759496

http://www.tsienlab.ucsd.edu/Publications/Ormo%201996%20Science%20-

%20Crystal%20structure.PDF

http://119.93.223.179/ScienceDirect/Current%20Biology/06-02/sdarticle_022.pdf

http://pubs.acs.org/doi/pdf/10.1021/bi00056a003

Assignment 2: GFP articles

GFP: Green Fluorescent Protein

•  "Engineering green fluorescent protein for improved brightness, longer wavelengths and fluorescence resonance energy transfer" article by Heim and Tsien tells us that GFP are important for at least three reasons. First, to provide distinguishable markers to observe events going on in a cell simultaneously. Second, to serve as donors and acceptors for fluorescence resonance energy transfer (FRET). Third, to illuminate the structure–function relationship of an intrinsically fascinating protein. Variants of the green fluorescent protein, GFP, with different colors would be very useful for simultaneous comparisons of multiple protein fates, developmental lineages and gene expression levels. Their results demonstrate that the production of more and better GFP variants is possible and worthwhile. The production of such variants facilitates multicolor imaging of differential gene expression, protein localization or cell fate. 

http://119.93.223.179/ScienceDirect/Current%20Biology/06-02/sdarticle_022.pdf

• "Crystal structure of the Aequorea victoria Green fluorescent protein" by kormo, cubitt, et al. tells us that the cloning and heterogenous expression of GFP's cDNA were the crucial steps that triggered the widespread and growing use of GFP as a reporter for gene expression and protein localization. GFP is a stable, proteolysis-resistant single chain of 238 residues and has two absorption maxima at about 395 and 475 nm. The relative amplitudes of these two peaks are sensitive to environmental factors and illumination. GFP provides an elegant example of how a visually appealing and useful "function-efficient" fluorescence can be spontaneously generated from a cohesive and economical protein stricture. 

 http://www.tsienlab.ucsd.edu/Publications/Ormo%201996%20Science%20-

%20Crystal%20structure.PDF

• The article, "Chemical Structure of the Hexapeptide Chromophore of the Aequorea Green-Fluorescent Protein?" by Cody, Prasher, et al. tells us that the GFP proteins are a unique class of proteins involved in the bioluminescence of many cells and organisms. The GFPs serve as energy-transfer acceptors, receiving energy from either a luciferase-oxyluciferin complex or a Ca2+ activated photoprotein, depending on the organism. Upon mechanical stimulation of the organism, GFP emits green light spectrally identical to its fluorescence emission. These highly fluorescent proteins are unique due to the nature of the covalently attached chromophore, which is composed of modified amino acid residues within the polypeptide.

 http://pubs.acs.org/doi/pdf/10.1021/bi00056a003

Assignment 1

GFP: GREEN FLUORESCENT PROTEIN

by Anika Farhan

GFP 1

GFP 2

GFP 3

GFP 4

GFP 5