Effects of anthracycline antibiotic, daunomycin on thymus chromatin: the role of chromosomal proteins.

1. We have examined the effect of antitumour antibiotic daunomycin on calf thymus chromatin employing u.v./vis spectroscopic and hydrodynamic techniques. The experiments were undertaken to determine the influence of added drug on DNA-protein complex. 2. The results show that the binding of drug to chromatin is dose dependent and a DNA to drug ratio below 1:100 leaves small oligonucleotides in the supernatant, however, at higher ratios chromatin occurs aggregation. 3. Analysis of both the proteins and DNA reveals that daunomycin induces chromatin condensation by cross linking between its components suggesting that chromosomal proteins play a significant role in this process.