Estimation of the extent of DNA platination after interaction of cis-DDP with DNA and chromatin.

The aim of this work was to compare the kinetics of platinum binding to "naked" DNA and DNA remaining in a nucleoprotein complex. The incubation of chromatin and DNA from calf thymus was carried out with cis-DDP at different concentrations and incubation times. The coefficient rb/mumolPT/mumolDNA/ of platinum binding to DNA was determined and the kinetics of cis-DDP binding to particular preparations was found and compared. The presence of chromosomal proteins decreases the extent of DNA platination. Hence it can be suggested that this drug induces the process of chromatin aggregation and condensation which in turn reduce the release of the total pool of DNA.