Abstract
Immunochemical analysis was employed to investigate the cell cycle-dependent protein-DNA crosslinking by
cis-diamminedichloroplatinum II (
cis-DDP), in HeLa-S
3 cells. Cells synchronized by double thymidine block or hydroxyurea were released into S phase and incubated at 2-h intervals with
cis-DDP as they progressed through S
1, G
2, M, and then into G
1 and S phases of the subsequent cycle. Immunoblots of the DNA-crosslinked antigens reacted with antisera to 0.35
m NaCl extract or residue of HeLa S-phase nuclei revealed that several antigens changed their DNA-crosslinking pattern during the progression of HeLa cells through their reproductive cycle.