[Comparative study of nucleosome particles in chromatin from normal and tumor cells. I. Structural parameters].

The composition and structure of nucleosomic fragments isolated from the ascitic hepatoma 22A cells, liver and from cells of C3HA mice in norm and after partial hepatectomy were investigated. Via electrophoresis in 1.5% agarose gel with the emplogment of reperic restrictive DNA fragments and with the help of mathematical processing, the value of the nucleosomic DNA repeat in ascitic hepatoma 22A was calculated to be 187 b.p., and in regenerating liver--196 b.p. The absence of the H1 degree subfraction in chromatin of ascitic hepatoma 22A cells was found. Lower electrophoretic mobility in 5% polyacrylamid gel of nucleosomic chromatin fragments of ascitic hepatoma 22A as compared with their counterparts from healthy mice liver was established. The method of circular dichroism allowed to reveal differences in the RNA and protein structural state in nucleosomes of normal and tumour cells. The structure of nucleosomes of regenerating mice liver of the C3HA strain did not differ from that of normal liver of the same mice.