1.
Biokhimiia
; 59(12): 1852-9, 1994 Dec.
Article
in Russian
| MEDLINE
| ID: mdl-7873684
ABSTRACT
DNA-dependent RNA polymerase IIB having a specific activity of 320 u./mg has been isolated from the term placenta homogenate using extraction performed at 4-6 degrees C in the presence of 75 mM ammonium sulfate and 1.5% nonidet P40, fractionation on DEAE-cellulose DE 23, desalting and heparin-agarose chromatography, resulting in 330-fold purification and a 18% yield. Technical details have been determined which are of crucial importance for reproducibility of affinity chromatography. The possibility of proteolysis of the IIc subunit during enzyme purification has been demonstrated.