Green fluorescent protein fragment

Branchini, B. R., Lusins, J. O., and Zimmer, M. (1997). A molecular mechanics and database analysis of the structural preorganization and activation of the chromophore-containing hexapeptide fragment in green fluorescent protein. /. Biomol. Struct. Dyn. 14 441-448. 

CP coat protein CtxB cholera toxin B subunit scFv single chain Fv antibody fragment TMOF trypsin modulating oostatic factor MAB monoclonal antibody GFP green fluorescent protein CPV Canine parvovirus BHV Bovine herpes virus FMDV Foot and mouth disease virus HCV Hepatitis C virus HRV Human rhino Virus MEV Mink enteritis virus MHV Murine hepatitis virus MV Measles virus RSV Respiratory syncytial virus... 

More recently Michnick and co-workers have introduced a dihydrofolate reductase complementation system, which seems to be particularly robust [61 - 65], They attribute the success of this system to the fact that the N-terminal (1 - 105) and C-terminal (106 - 186) DHFR fragments do not fold until they are dimerized. In addition to the obvious selection for essential metabolites dependent on the reduction of dihydrofolate to tetrahydrofolate, protein-protein interactions are detected based on the retention of a fluorescein-methotrexate conjugate. Several other enzymes have been employed for the design of complementation assays, including green fluorescent protein, which allows screens based on fluorescence or FRET [66 - 68]. As with the bacterial transcription assays, these complementation systems are new. It will be interesting to see if, as the selections are optimized, these systems prove competitive with the Y2H assay. 

Other reports show that intracellular expression of misfolded or unstable proteins can be dramatically improved by directed evolution. For example, directed evolution increased the expression of disulfide-containing antibody fragments in E. coli 50-fold, to reach a level of more than 0.5 g/L 212L The expression of a wide spectrum amidase of B. stearothermophilus in E. coli was improved 23-fold by two mutations 2101. And, in vivo fluorescence of the green fluorescent protein was improved 45-fold by increasing its solubility and native folding in E. co/t[1401. 

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