Linked Life Data

128455

Source:http://linkedlifedata.com/resource/pubmed/id/128455

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-4-2
pubmed:abstractText
The mechanism of protein synthesis inhibition by the toxic lectins, abrin and ricin, has been studied in crude and in purified cell-free systems from rabbit reticulocytes and Krebs II ascites cells. In crude systems abrin and ricin strongly inhibited protein synthesis from added aminoacyl-tRNA, demonstrating that the toxins act at some point after the charging of tRNA. Supernatant factors and polysomes washed free of elongation factors were treated separately with the toxins and then neutralizing amounts of anti-toxins were added. Recombination experiments between toxin-treated ribosomes and untreated supernatant factors and vice versa showed that the toxin-treated ribosomes had lost most of their ability to support polyphenylalanine synthesis, whereas treatment of the supernatant factors with the toxins did not inhibit polypeptide synthesis. Recombination experiments between toxin-treated isolated 40-S subunits and untreated 60-S subunits and vice versa showed that only when the 60-S subunits had been treated with the toxins was protein synthesis inhibited in the reconstituted system. The incorporation of [3H]puromycin into nascent peptide chains was unaffected by the toxins, indicating that the peptidyl transferase is not inhibited. Both the EF-1-catalyzed and the EF-2-catalyzed ability of the ribosomes to hydrolyze [gamma-32P]GTP was inhibited by abrin and ricin. An 8-S complex released from the 60-S subunit by EDTA treatment possessed both GTPase and ATPase activity, while the particle remaining after the EDTA treatment had lost most of its GTPase activity. Both enzyme activities of the 8-S complex were inhibited by abrin and ricin. The present data indicate that there is a common site on the 60-S subunits for EF-1- and EF-2- stimulated GTPase activity and they suggest that abrin and ricin inhibit protein synthesis by modifying this site.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
573-80
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
On the mechanism of protein-synthesis inhibition by abrin and ricin. Inhibition of the GTP-hydrolysis site on the 60-S ribosomal subunit.
pubmed:publicationType
Journal Article