Half-life of Gfp(ASV)

Value 110 min
Organism Bacteria Escherichia coli
Reference Andersen JB, Sternberg C, Poulsen LK, Bjorn SP, Givskov M, Molin S. New Unstable Variants of Green Fluorescent Protein for Studies of Transient Gene Expression in Bacteria. Appl Environ Microbiol. 1998 Jun64(6):2240-6. p.2244 right column 2nd paragraphPubMed ID9603842
Method P.2244 right column 2nd paragraph: "In order to estimate the half-lives of the mature Gfp variants in vivo, [investigators] carried out quantitative fluorometer measurements of green fluorescence expressed by the strains derived from E. coli MV1190(λ-pir) or P. putida KT2442 (lacI q) encoding the variant Gfps (the same strains used for the colony investigations). The strains were grown in rich medium and shifted at mid-log phase to minimal medium without inducer. After the shift there was no increase in OD450 for 4 to 5 h, which means that protein synthesis (including that of Gfp) was negligible during this period. Fluorescence was measured at time intervals after the shift (Fig. 3). The stability of Gfpmut3* and the four tagged versions was estimated by using the relative green fluorescence value as a function of the time after the shift, represented as the slopes of the curves in Fig. 3."
Comments P.2244 right column 2nd paragraph: "In E. coli it was found that the green fluorescence of Gfp(LAA), Gfp(LVA), Gfp(AAV), and Gfp(ASV) in the absence of Gfp synthesis decreased linearly from T = 10 min to T = 80 min after the downshift (Fig. 3A). The slope constants, μ, were determined to be approximately −0.018 min^−1 for the strains encoding Gfp(LAA) and Gfp(LVA) and −0.012 and −0.0062 min^−1 for the strains encoding Gfp(AAV) and Gfp(ASV), respectively. This corresponds to in vivo half-lives of mature Gfp(LAA) and mature Gfp(LVA) of approximately 40 min (T 1/2 = −ln 2/μ), while Gfp(AAV) and Gfp(ASV) appear to have half-lives of approximately 60 and 110 min, respectively. In striking contrast, mature Gfpmut3* appears completely stable within the time of the experiment. This is in accordance with previous observations that both colonies and liquid cultures of E. coli MV1190(λ-pir) expressing Gfpmut3* remain green fluorescent after several weeks of incubation (data not shown)."
Entered by Uri M
ID 105188