Plasmids integrative

In view of the importance of the microencapsulating procedure that produces microspheres in the desired size and size distribution and preserves DNA plasmid integrity, the detailed procedure is provided as follows. 

Different tissues have been shown to display different DNA pharmacokinetics. Genes and gene products have been observed as long as 19 months after direct injection without indication of plasmid integration or replication (175). Direct injection of the chloramphenicol acetyltransferase gene into the thyroid resulted in elimination of DNA from the gland with a half-life of 10 hours. The enzyme activity was maximal for 24 hours and eliminated through first-order kinetics with an apparent half-life of 40 hours (176). Similar results were recorded for synovial fluid intra-articular administration of plasmid DNA (177). 

Auvray F, Codderville M, Ritzenthaler P, Dupont L (1997) Plasmid integration in a wide range of bacteria mediated by integrase of Lactobacillus delbrueckii bacteriophage mv4. J Bacteriol 179 1837-1845 Babel W, Iske U, Jechorek M, Miethe D (1987) Method for production of products by fermentation of methanol. German Patent GDR 251,571. ChemAbstr 109 36639... 

One method used to achieve genetic stabiUty is to insert the plasmid or the recombinant DNA direcdy into the chromosome. Since no cell can afford to lose a chromosome, this assures that the recombinant DNA is not lost as long as it remains an integral part of the chromosome. 

In the previous sections it was demonstrated that the stimulus-responsive behavior of ELP was transferred to ELP fusion proteins and even to non-covalently bound moieties, such as proteins, plasmids, and heavy metals, mostly for biomedical and biotechnological applications. The ability of ELPs to reversibly switch their polarity is also of great interest for the development of stimulus-responsive materials. Many approaches have therefore recently been undertaken to integrate ELPs with, for example, polymers, particles, and surfaces. 

The alkane hydroxylase belongs to a family of nonheme iron oxygenases. There is some structural similarity between the nucleotide sequence of the integral-membrane alkane hydroxylase and the subunits of the monooxygenase encoded by xylA and xylM in the TOL plasmid that are involved in hydrox-ylation of the methyl groups in toluene and xylene in Pseudomonas putida PaWl (Suzuki et al. 1991). 

Yeast-bacteria shuttle plasmids are usually able to be maintained in both E. coli and yeast and can be episomal or integrated into the host genome. First, plasmid DNA is usually amplified in E. coli before yeast gets transformed. Different antibiotic resistance cassettes are available, and also an abundance of autotrophic markers was established. 

Several areas are receiving much of the research attention. Approaches that integrate product recovery with the fermentation in a three-phase fluidized bed bioreactor reflect general research trends in biochemical engineering (Yabannavar and Wang, 1991 Davison and Thompson, 1992). The successful use of three-phase biofluidization has also been demonstrated for recombinant protein systems, where it may have some benefit in improving plasmid stability (Shu and Yang, 1996). 

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