DNA supercoiling of recombinant plasmids in mammalian cells.

DNA supercoiling of recombinant plasmids in mammalian cells.

We have used chloroquine/agarose gel electrophoresis and a blot-hybridization technique to study the modulation of superhelicity of extrachromosomal DNA in mammalian cells. The high sensitivity of the procedure has allowed us to measure the change in the specific linking difference or superhelical density (sigma) of a plasmid, psvo alpha 1p3d, after its introduction into COS-7 cells by DNA tran...

Energetic and Structural Inter - relationship between and the Right - to Left - handed Z Helix Transitions in Plasmids * DNA Supercoiling Recombinant

We have evaluated the B to Z conformational transitions in supercoiled recombinant plasmids containing different lengths of (dC-dG) described in the preceding paper. The sodium chloride-induced rightto lefthanded transition in a small segment of the plasmids caused a relaxation of (-) supercoils which was monitored by electrophoretic mobility changes of individual topoisomers on agarose gels c...

Expression of Biologically Active Recombinant B-Domain-Deleted Human Factor VIII in Mammalian Cells

Chromosomal integration of transduced recombinant baculovirus DNA in mammalian cells.

Our group and others have recently demonstrated the ability of recombinant baculoviruses to transduce mammalian cells at high frequency. To further characterize the use of baculovirus as a mammalian gene delivery system, we examined the status of transduced DNA stably maintained in Chinese hamster ovary (CHO) cells. Four independent clones carrying two introduced markers, the genes for neomycin...

Expression of recombinant plasmids in mammalian cells is enhanced by sodium butyrate.

We have studied the effects of sodium butyrate on DNA-mediated gene transfer in an effort to investigate interrelationships between chromatin structure and expression of recombinant plasmids. Our results demonstrate that butyrate affects the early stages of gene activity following DNA uptake at least two levels. First, the number of cells able to express foreign DNA increases from 10% to up to ...