Nucleic Acids Research, 1978, Vol. 5, No. 12 4905-4918
© 1978
Articles |
Complex of DNA with chromatin proteins investigated by isopycnic centrifugation in metrizamide
yDepartment of Tumor Biology, Institute of Oncology 44-100 Gliwice, Poland
Received August 14, 1978. Complexes of mouse main band DNA with a fraction of nonhistone proteins (NHP), having a high affinity for DNA, in the absence or presence of histones have been investigated by gradient centrifugation in metrizamide. Two types of complexes were formed at an input ratio of NHP to DNA between 1 and 2.5. In metrizamide gradients a majority of DNA was found in the light complex (at the density of 1.14 1.16 g/cm3) even at the very high NHP to DNA ratio. When histones were present in the reaction mixture, most of the DNA was found in the heavy complex (1.19 1.21 g/cm3). The eleotrophoretic profiles of the proteins recovered from the heavy and light complexes were different; some fractions of nonhistone proteins were present only in the heavy component.