PROTEIN SYNTHETIC ACTIVITY OF CHROMATOGRAPHICALLY ISOLATED MAMMALIAN RIBOSOMES

Ribosomes isolated from rat liver and rabbit reticulocytes by chromatography on ECTHAM-cellulose were active in vitro in an amino acid incorporating system. Microsome- containing fractions of rat liver, when subjected to the column procedure, yielded monosomes emerging in two peaks (RNP-I and -II), and these required the addition of synthetic polynucleotide for activity. RNP-I could function at a high level without the addition of “pH 5 enzymes” or soluble fraction. Chromatography of rabbit reticulocyte lysate yielded a single ribosomal peak (in the position of RNP-I) which contained active polysomes and, unlike the RNP-I obtained from rat liver, did not change its position on rechromatography. Purified pentameric ribosomes from reticulocytes were chromatographed without change in sedimentation rate or activity. © 1969, American Chemical Society. All rights reserved.