Green Fluorescent Protein

Green Fluorescent Protein Structure

greenfluorescentprotein — Fri, 18 May 2007 06:29:51 +0000

GFP, Green Fluorescent Protein, its structure was solved in the late 1996. It is said to have a unique soda can. Eleven beta-strands make up the beta-barrel and an alpha-helix runs through the center. The LIGHT IN THE CAN which is located in the middle of the beta barrel is called occasionally and is referred to as the microscopic chromophore. The remarkable cylindrical fold of the protein seems ideally suited for the function of the microscopic protein. Studies and research states that strands of -sheet are tightly fitted to each other like staves in a barrel, and form a regular pattern of hydrogen bonds. Together with the short -helices and loops on the ends, the ‘can’ structure forms a single compact domain and does not have obvious clefts for easy access of diffusable ligands to the microscopic fluorophore. This fold, taken with the observation of a microscope that the microscopic fluorophore is near the geometric center of the molecule explains the observed protection of the microscopic fluorophore from collisional quenching by oxygen and hence reduction of the quantum yields. Perhaps more seriously, photochemical damage by the formation of singlet oxygen through intersystem crossing is reduced by the structure. The tightly constructed can would appear to serve this role nicely says the researchers in Washington, as well as provide overall stability and resistance to unfolding by heat and denaturants. (more…)

Engineering GFP

greenfluorescentprotein — Fri, 18 May 2007 06:28:56 +0000

It is known to some scientist and researchers that the uses of GFP, Green Fluorescent Protein are also expanding into the world of art and commerce. Scientist and researcher Eduardo Kac has created a fluorescent green rabbit by engineering GFP into its cells with the help of a microscope. Breeders are exploring GFP, Green Fluorescent Protein as a way to create unique fluorescent plants and fishes. GFP has been added to rats, mice, frogs, flies, worms, and countless other living things and of course, these engineered plants and animals are still controversial, and are spurring important dialogue on the safety and morality of genetic engineering. The availability of green fluorescent protein and its derivatives has thoroughly redefined fluorescence microscopy and the way it is used in cell biology and other biological disciplines. While most small fluorescent molecules such as FITC ,fluorescein isothiocyanate are strongly phototoxic when used in live cells, fluorescent proteins such as GFP are usually much less harmful when illuminated in living cells. This has triggered the development of highly automated live cell fluorescence microscopy systems which can be used to observe cells over time expressing one or more proteins tagged with fluorescent proteins. (more…)

Fluorescence Microscopy

greenfluorescentprotein — Fri, 18 May 2007 06:26:53 +0000

In order to be more familiar and understand microscopic substance of GFP, Green Fluorescent Protein, One must understand and learn how fluorescence microscopy works and why it has become so important to modern biology, one must understand what the term fluorescence means. Fluorescence is the luminescence of a substance when it is excited by radiation. In microscopy, fluorescence ,it is said that it is used as a means of preparing specific biological probes. Some biological microscopic substances like chlorophyll and some oils and waxes have primary fluorescence with in them that may emit light and glow on dark environments. That process is known to be autofluoresce. But most microscopic biological molecules or structures do not fluorescence on their own, so they must be linked with fluorescent molecules or fluorochromes in order to create specific fluorescent probes and therefore can emit light with in their own. Scientist and researchers from north America concluded and believes that Fluorescence of a substance is seen when the molecule is exposed to a specific wavelength of light ,excitation wavelength or spectrum, and the light it emits ,the emission wavelength or spectrum, is always of a higher wavelength. To view this fluorescence in the microscope, several light filtering components are said to be needed. Such specific filters are significantly needed to isolate the excitation and emission wavelengths of a microscopic fluorochrome. However, a bright light source with proper wavelengths for excitation is also needed. For normal fluorescence applications as such, this is a mercury vapor arc burner. For fluorescence confocal microscope applications where up to 95 percent of the emission light is filtered out, specific wavelength lasers are used as these are extremely bright that the naked human eye. Mercury arc burners are very bright lamps with a limited lifetime and might require some maintenance and care to make sure that they are producing the brightest possible light beam for fluorescence excitation. (more…)

The Green Fluorescent Protein or GFP

greenfluorescentprotein — Fri, 18 May 2007 06:25:38 +0000

GFP also known as Green Fluorescent Protein has existed for approximately one hundred and sixty million years in one species of jellyfish. Sometime in 1994 studies showed that GFP has been cloned. Now GFP is found in laboratories all over the world where it is used in every conceivable plant and animal. Flatworms, algae, E. coli and pigs have all been made to fluoresce with GFP. To some scientist and researchers, GFP is considered as the microscope of the twenty-first century. Using GFP we can see when proteins are made and where they can go with the aid of a microscope. It is said that it is done by joining the GFP gene to the gene of the protein of interest so that when the protein is made it will have GFP hanging off it. One of these scientist said are Osamu Shimomura whom was the first person to isolate GFP and to find out which part of GFP was responsible for its fluorescence with the use of microscope. His meticulous research laid the solid foundations on which the GFP revolution was built. Shimomura started studying the bioluminescence of the crystal jellyfish, Aequorea Victoria which is now widely used for experiments and tests. This jellyfish produces green bioluminescence from small photoorgans located on its microscopic umbrella. (more…)

Protein Functions

greenfluorescentprotein — Fri, 18 May 2007 06:24:02 +0000

Within the microscopic cell, proteins are said to be carrying out the duties specified by the information encoded in genes. Most biological molecules are relatively inert elements upon which proteins act, except for certain types of RNAs. The total complement of proteins expressed in a particular microscopic cell or cell type at a given time or experimental condition is known as proteome. The chief characteristic of proteins that enables them to carry out their many and different cellular functions is their ability to bind other molecules specifically and tightly. The region of the protein responsible for binding another molecule is known as the binding site. It is often seen under the microscope as a depression or “pocket” on the molecular surface. This binding ability is mediated by the tertiary structure of the protein. This tertiary structure defines the binding site pocket, and by the chemical properties of the surrounding amino acids’ side chains. Protein binding can be extraordinarily tight and specific. Proteins can bind to other proteins as well as to small-molecule substrates. Also possible are protein to protein binding. These protein to protein interactions regulate enzymatic activity and control progression in the cell cycle. This also allows the assembly of large protein complexes that carry out many biological function. Proteins can also bind to microscopic cell membranes. The ability of binding partners to induce conformational changes in proteins allows the possible construction of enormously complex signaling networks. (more…)

Protein

greenfluorescentprotein — Fri, 18 May 2007 06:21:55 +0000

Protein refers to any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur. Proteins are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of an organism. Proteins are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes. Protein constitutes three-fourths of our body tissue. Muscles, organs, antibodies, enzymes, and some hormones are largely composed of proteins. Other key body functions include tissue repair, fluid balance, blood clotting, and vision. Protein does not refer to a single substance but numerous chemical combinations. The proteins basic structure is composed of amino acid chains, which can form many different configurations and can combine with other substances. There are 22 amino acids identified in the protein of the human body. Proteins are constantly broken down in the body for metabolism. Most of these broken down proteins are reused by the body. However, some need to be replaced. There are nine proteins that are considered to be essential. These cannot be manufactured by the body and must be supplied by the persons diet. The necessary or the average protein requirement for women is 50 grams per day and 60 grams per day for men. Meat and other animal products are the most readily available sources of protein. The protein content of cooked meat and dairy products is between 15% and 40%. In contrast, it is believed that cooked cereals, beans, lentils, and peas range from 3% to 10%. As for vegetarians, people who don’t eat meat and meat products, can get enough protein if they eat a well-balanced diet of grains and vegetables, like brown rice, whole wheat pasta, soy products, and beans. (more…)