Conformational studies of nucleoprotein. Circular dichroism of deoxyribonucleic acid base pairs bound by polylysine

The effect of backbone structure on polycation comb-type copolymer/DNA interactions and the molecular assembly of DNA

“…The change of CD signal observed with ePLL and aPLL copolymers are typical for B-C-type transformation of DNA duplex whereas that observed with the PAA copolymers are similar to B-A-type transformation. B-C-type transformation was known to be induced by increasing ionic strength [18,19] or by addition of polyamines [20] whereas B-A-type transformation was observed at lower humidity. The B-A-type transformation was also reported for DNA/polyamine complex in water/EtOH mixture solution [21].…”

A stable alpha-helical element in the carboxy-terminal domain of free and chromatin-bound histone H1 from sea urchin sperm.

“…Similar CD spectral changes were observed in studies of poly-Llysine/DNA complexes and complexes of a random co-polymer of alanine and lysine (Lys, Ala)n with DNA (both of which might be considered as models for the prolinefree region of sperm H1). Although these were interpreted in terms of DNA distorted to C-form at low ionic strength (Chang et al, 1973;Pinkston and Li, 1974), and to the A-form in the presence of salt (Pinkston and Li, 1974), it seems likely that the true cause was alteration in the tertiary structure of DNA due to aggregation or condensation, which can have large effects on the CD spectrum (Ong et al, 1976). Calculated from the AE220 values shown in Table III assuming The values were calculated from the spectra shown in Figure 6.…”

Studies on the compaction of isolated nucleoids from Escherichia coli

“…Optical properties of reisolated preparations of expanded nucleoids suggested the presence of partially annealed complexes of DNA with polylysine (Carroll, 1972;Chang et al, 1973). The lysate DNA was hyperchromic relative to samples treated with 1 M NaCl to dissociate ligands (Table 2), a characteristic of polylysine-DNA complexes.…”