Protein composition of DNA-matrix complexes with "strong" and "weak" types of bonds, isolated from Ehrlich ascites carcinoma cells

• Published in: Biokhimiia (Moscow, Russia) Vol. 54; no. 7; p. 1217
• Main Authors: S'iakste, N I, Blokhin, D Iu
• Format: Journal Article
• Language: Russian
• Published: Russia (Federation) 01-07-1989
• Subjects: Animals; Carcinoma, Ehrlich Tumor - metabolism; Chromatography, Gel; DNA Restriction Enzymes; DNA-Binding Proteins - isolation & purification; DNA-Binding Proteins - metabolism; Electrophoresis, Polyacrylamide Gel; Tumor Cells, Cultured - metabolism
• ISSN: 0320-9725

A preparative procedure for obtaining tightly and loosely bound DNA-matrix complexes was developed. To this end, the DNA-matrix complexes were separated from DNA excess by restrictase digestion and solubilized in 0.1% sodium dodecyl sulfate + 8 M urea. To obtain tightly bound complexes, the lysate was transferred to a solution containing 2 M LiCl and 4 mM urea and gel filtered in the same medium. Tightly bound complexes were eluted in the same peak with DNA. Loosely bound complexes were obtained by gel filtration in 0.1% sodium dodecyl sulfate + 8 M urea after preliminary digestion of the original complexes with DNAase I which selectively destroys the tight bonds. Within the composition of loosely bound DNA-matrix complexes, the polypeptides with Mr of 180, 65-75, 58 and 47-50 kDa were identified, whereas tightly bound complexes were shown to contain polypeptides with molecular masses of 180, 65-75, 63, 61, 58 and 52-53 kDa.