title: Inhibition of protein synthesis by ricin: experiments with rat liver mitochondria and nuclei and with ribosomes from Escherichia coli.
abstract: 1. Ricin, a toxic protein from the seeds of Ricinus communis which inhibits poly(U)-directed polyphenylalanine synthesis by rat liver ribosomes (Montanaro et al., 1973), does not affect protein synthesis by isolated rat liver mitochondria. 2. The toxin is ineffective also on poly(U)-directed polyphenylalanine synthesis in reconstituted systems with ribosomes isolated from rat liver mitochondria or from Escherichia coli. 3. Ricin inhibits protein synthesis by isolated rat liver nuclei, but at concentrations much higher than those affecting rat liver ribosomes.
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D010940:Plant Proteins / Q000494:pharmacology*; D011072:Poly U; D014176:Protein Biosynthesis / Q000187:drug effects*; D051381:Rats; D012269:Ribosomal Proteins / Q000096:biosynthesis; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*; D012276:Ricin / Q000494:pharmacology*; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; D012269:Ribosomal Proteins; D011072:Poly U; D010649:Phenylalanine; D012276:Ricin