Labelling pattern of the nonhistone chromosomal proteins in quiescent and dividing Ehrlich ascites tumour cells.

Upon pulse-labelling with [14C]protein hydrolizate both in dividing and quiescent Ehrlich ascites tumour (EAT) cells the nonhistone chromosomal (NHC) proteins had uniform specific radioactivity with few exceptions: Both in quiescent and dividing EAT cells a polypeptide with molecular weight of about 200 kdalton had specific radioactivity 2-3 times lower than that of the most of the NHC proteins. In the actively proliferating cells a group of proteins with molecular weights between 45 and 65 kdalton had 2-3 times higher specific radioactivity than most of the NHC proteins. In quiescent cells the specific radioactivity of a group of proteins with molecular weights in the range 18-25 kdalton was 3-4 times higher than that of the rest of the NHC proteins.