Since debye distance nearly equal to radius of DNA and
supercoil assumed to be in ionic solution hence the effect of repulsion between the two strands at a distance s can be expressed in a dimensionless term as
Then they bend and twist again, folding into gnarled
supercoils.
The size of the
Supercoils makes them suitable for use in cooling metal-plating baths.
Furthermore, Top II-mediated DNA
supercoil relaxation is stimulated by the Drosophila protein Barren [267], which is involved in chromosome condensation and disjunction [268].
The cleavage activity was demonstrated by gel-electrophoresis experiments using
supercoiled (SC) plasmid pBR 322 DNA in a medium TAE buffer.
This results in accumulation of positively
supercoiled DNA, which causes transcription and replication initiation failure with depletion of mitochondrial DNA copy number.
were monitored by conversion of
supercoiled plasmid pBR322 DNA to open circular form as described by Yeung et al.
The CT-DNA binding and
supercoiled pentry/d-topo plasmid DNA cleavage activities of copper complexes were also evaluated.
The experiment was accomplished with
supercoiled pUC18 (200 ng, 1 [micro]L) which was treated with varying concentrations of compounds (10-50 [micro]M) in Trisboric acid-buffer with NaCl (50 mM, pH 7.2) by agarosegel electrophoresis method.
Top II plays a key role in relaxing
supercoiled DNA for replication and transcription in the absence of inhibitors [38], while the presence of inhibitors forms a stable complex with the enzyme and keeps it from DNA cleavage [39].