Metrizamide gradient centrifugation of histone-DNA complexes.
Mouse DNA was complexed with different combinations of histones. Most of these complexes were separated in metrizamide gradient into two fractions--heavy and light. At the protein: DNA ratio of 0.8 a complex of DNA with five histones contained 60% of DNA in the heavy fraction whereas in the absence of histone H1, this fraction contained only 40% of DNA. Complexes of DNA with the H2A + H2B histone pair banded in metrizamide as one, light fraction at the density of 1.140 g/cm3. DNA reconstituted with the H3 + H4 histone pair formed in metrizamide two peaks of 1.240 g/cm3 and 1.140 g/cm3. Among complexes of DNA with single histones H2A, H2B, H3 and H4 only the complex DNA-H4 formed a component having in metrizamide a density of 1.200 g/cm3, similar to the density of purified chromatin.
D000818:Animals; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient / Q000379:methods; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA / Q000302:isolation & purification*; D006657:Histones / Q000302:isolation & purification*; D007668:Kidney / Q000378:metabolism; D008793:Metrizamide; D051379:Mice; D051381:Rats
D006657:Histones; D004247:DNA; D008793:Metrizamide