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Green Fluorescent protein. Samantha Stickdorn. Discovery. Discovered by Osamu Shimoura in 1962 First discovered in Aequorea Victoria a hydrozoan jellyfish species he extracted the protein from a faintly luminescent liquid called squeezate
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Green Fluorescent protein Samantha Stickdorn
Discovery • Discovered by Osamu Shimoura in 1962 • First discovered in Aequorea Victoria a hydrozoan jellyfish species • he extracted the protein from a faintly luminescent liquid called squeezate • Obtained when the rings of twenty to thirty jellyfish are squeezed through a rayon gauze,
Nobel Prize • Osamu Shimoura, Martin Chalfie, and Roger TsienWon noble prize in 2008 for their work with GFP • Osamu Shimourais credited with discovering the protein • Martin Chalfie demonstrated the value of GFP as a luminous genetic tag for various biological phenomena. • Roger Y. Tsiencreated mutations of the protein to create a wide variety of colors whichenabled scientists to follow several different biological processes at the same time. • Osamu Shimoura Martin Chalife Roger Tsien
Structure and function • .Eleven beta-strands make up the beta-barrel and an alpha-helix runs through the center • Cylindrical beta barrel structure helps protect chromophore • Exhibits bright green fluorescence when exposed to light in blue to ultraviolent range
How it works • Jelly fish relsease calcium ions that bind to protein called aequorin • Produces blue light • GFP absorbs blue light and gives off green light • Process occurs in photoorgans located on the umbrella
Uses: tracer molecule • GFP gene is inserted after the desired protein gene and before stop codon • ultra violet light causes the GFP attached to the protein to fluoresce allowing the protein to be traced as it moves through the cell
Uses: Reporter gene • Can be used to determine function of a protein • When Placed under the control of a specific promoter GFP will be expressed in place of protein showing where and when the gene of interest is switched on.
Applications • Gene expression and function • Unknown Proteins can be tagged to see where they are expressed in the body • Animals remain alive so proteins can be seen in action • See when genes are turned on and off • Allows researchers to easily see structures • Researchers labeled neurons in brains of mice • Watch mice think by observing reactions in the brain to whisker stimulus
Applications continued • Used to study diseases like cancer and Alzheimer's • Cancer cells labeled with GFP inserted into mice so they can watch how it grows and spreads • nerve cell damage during Alzheimer's disease can be observed • Biosensors • contaminants in the environment • pH and ion concentration fluctuations • Map intracellular temperature
avantages • GFP isn’t toxic to cells like some traditional dyes • Can be used to monitor cellular processes in living cells and organism • It’s small size makes it less likely to hinder function of attached protein • Doesn't require additional substances to produce fluorescence
Mutations • Mutation to enhance brightness • Several different mutations have been created leading to a wide variety of colors
References • . "Fluorescent protein technology." Zeiss microscopy online. Carl Zeiss Microscopy, 2012. Web. 30 Nov 2012. <http://zeiss-campus.magnet.fsu.edu/articles/probes/fpintroduction.html • marc, Zimmer. "Green Fluorescent Protein." . Connecticut college, 3 2012. Web. 30 Nov 2012. <http://www.conncoll.edu/ccacad/zimmer/GFP-ww/GFP-1.htm >. • Shimomura, O., Johnson, F. H. and Saiga, Y. (1962), Extraction, Purification and Properties of Aequorin, a Bioluminescent Protein from the Luminous Hydromedusan, Aequorea. J. Cell. Comp. Physiol., 59: 223–239. doi: 10.1002/jcp.1030590302 • Chalfie, M. (1995), GREEN FLUORESCENT PROTEIN. Photochemistry and Photobiology, 62: 651–656. doi: 10.1111/j.1751-1097.1995.tb08712.x