User:Michael Patrick/Sandbox 2: Difference between revisions
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Redox sensitive versions of GFP (roGFP) were engineered by introduction of cysteines into the beta barrel structure[14]. The redox state of the cysteines determines the fluorescent properties of roGFP | Redox sensitive versions of GFP (roGFP) were engineered by introduction of cysteines into the beta barrel structure[14]. The redox state of the cysteines determines the fluorescent properties of roGFP | ||
The nomenclature of modified GFPs is often confusing due to overlapping mapping of several GFP versions onto a single name. For example, mGFP often refers to a GFP with an N-terminal palmitoylation that causes the GFP to bind to cell membranes. However, the same term is also used to refer to monomeric GFP, which is often achieved by the dimer interface breaking A206K mutation.[15] Wild-type GFP has a weak dimerization tendency at concentrations above 5 mg/mL. mGFP also stands for "modified GFP," which has been optimized through amino acid exchange for stable expression in plant cells. | The nomenclature of modified GFPs is often confusing due to overlapping mapping of several GFP versions onto a single name. For example, mGFP often refers to a GFP with an N-terminal palmitoylation that causes the GFP to bind to cell membranes. However, the same term is also used to refer to monomeric GFP, which is often achieved by the dimer interface breaking A206K mutation.[15] Wild-type GFP has a weak dimerization tendency at concentrations above 5 mg/mL. mGFP also stands for "modified GFP," which has been optimized through amino acid exchange for stable expression in plant cells. | ||
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===STRUCTURE=== | |||
<Structure load='1ema' size='500' frame='true' align='right' caption='GFP in backbone format and spacefill chromophore' scene='User:Michael_Patrick/Sandbox_2/Ema-1/1' /> | |||
GFP has a typical beta barrel consisting of <scene name='User:Michael_Patrick/Sandbox_2/Ema-2/3'>one β-sheet</scene> with <scene name='User:Michael_Patrick/Sandbox_2/Ema-3/2'>alpha helix(s) containing the chromophore running through the center.</scene> Inward-facing sidechains of the barrel induce specific cyclization reactions in the tripeptide Ser65–Tyr66–Gly67 that lead to chromophore formation. This process of post-translational modification is referred to as maturation. The hydrogen-bonding network and electron-stacking interactions with these sidechains influence the color of wtGFP and its numerous derivatives. The tightly packed nature of the barrel excludes solvent molecules, protecting the chromophore fluorescence from quenching by water. | |||
