The fractionation of calf thymus DNA on histone KAP-Sepharose 4B columns

It was found that fractionation of calf thymus DNA on homologous histtone KAP covalently bound to CNBr activated Sepharose 4B depends on the molecular weight of DNA. The maximum of elution of high molecular DNA (m. wt. above 5 x 10(6)) was observed at 0.56 M NaCl and that of degraded DNA (m. wt. 0.8 x 10(6)) at 0.52 M NaCl. Significant differences in melting temperatures and melting intervals were observed among fractions obtained from low molecular DNA as a result of enrichment of some fractions in satellite DNAs. These differences were very small in DNA of m. wt. above 5 x 10(6). The results are discussed in terms of specific areas which may exist on calf thymus DNA molecules playing the role of loci, where lysine-rich histone KAP is preferentially bound.