Biochemistry 7: 3149-55 (1968)
The nonhistone protein of interphase chromatin of rat liver has been isolated, using sodium dodecylsulfate, and partially characterized. The chromosomal nonhistone protein is rich in acidic amino acids and contains tryptophan. The physical state of chromosomal nonhistone protein is markedly dependent upon detergent. In the presence of detergent (0.1 %) the nonhistone protein gives S(20,W) of 2.7 S and an average molecular weight of 14,300. On removal or lowering of detergent concentrations the protein aggregates. The chromosomal nonhistone protein interacts with histones to form an insoluble complex under appropriate conditions. A chromosomal nonhistone protein-deoxyribonucleic acid complex can he made by a NaCI gradient dialysis of mixtures of deoxyribonucleic acid and the nonhistone protein. Such a complex shows the same activity in support of ribonucleic acid synthesis as does pure deoxyribonucleic acid.