Activation in vitro of rat liver polyribosomes.
The increase in the incorporation of amino acids into protein in vitro by preparations obtained from protein-fed rats as compared with preparations obtained from carbohydrate-fed rats has been described previously. After molecular sieving through Sephadex G-25 of cell-free preparations, the difference in incorporating activity between the two types of rats was diminished in systems containing ATP, phosphoenolpyruvate, pyruvate kinase, GTP, and a mixture of amino acids. When, after molecular sieving, a mitochondrial (15,000 g) supernatant was incubated for 4 min at 35 degrees C the polysomal pattern of the preparations was unchanged. In the presence of ATP, phosphoenolpyruvate, and pyruvate kinase the polysomal incorporating activity was low and the polysomal pattern was only slightly changed. Addition of GTP increased the activity markedly, and a more pronounced activity was observed when a mixture of amino acids was added as well. As the amino acid incorporation ability increased, monosomes were formed from the polyribosomes. The activity of the polyribosomes was severalfold higher than that of non-Sephadex-treated preparations, indicating an activation of polysomal aggregates which under the usually applied conditions of incubation and prior to molecular sieving show little or insignificant activity. It was possible to activate polyribosomes from carbohydrate-fed and protein-fed rats to almost the same extent.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D002247:Carbon Isotopes; D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D004040:Dietary Carbohydrates / Q000494:pharmacology; D004044:Dietary Proteins; D005260:Female; D006150:Guanine Nucleotides / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D011770:Pyruvate Kinase / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism; D051381:Rats; D012270:Ribosomes / Q000378:metabolism*
D000596:Amino Acids; D002247:Carbon Isotopes; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D006150:Guanine Nucleotides; D011773:Pyruvates; D000255:Adenosine Triphosphate; D011770:Pyruvate Kinase; D007930:Leucine
Cancer Res. 1966 Feb;26(2):253-7
5903176
J Mol Biol. 1966 Sep;20(1):113-21
5970656
J Cell Biol. 1967 Jun;33(3):657-63
6036528
Eur J Biochem. 1968 Mar;4(1):87-94
5646149
J Mol Biol. 1968 Jul 14;34(2):199-218
5760456
J Biol Chem. 1951 Nov;193(1):265-75
14907713
J Histochem Cytochem. 1956 Jan;4(1):1-10
13295564
Nature. 1963 Feb 2;197:430-5
14000153
Arch Biochem. 1950 Feb;25(2):262-76
15404816