Comparison of effects of L-tryptophan and a tryptophan analog, D,L-beta-(1-naphthyl)alanine, on processes relating to hepatic protein synthesis in rats.
Earlier studies reported that the administration of L-tryptophan increased polyribosomal aggregation, protein synthesis and levels of cytoplasmic poly(A) mRNA in rat liver. This study was concerned with the effects of an L-tryptophan analog, D,L-beta-(1-naphthyl)alanine, in comparison with those of L-tryptophan. Both D,L-beta-(1-naphthyl)alanine and L-tryptophan bound to the L-tryptophan receptor protein and increased poly(A)polymerase and nucleoside triphosphatase activities of hepatic nuclei. However, only L-tryptophan was associated with increases in the release of labeled nuclear RNA (in vitro), in protein synthesis, in polyribosomal aggregation and in glycosylation ([14C]glucosamine incorporation into proteins) of rat liver. These results indicate that although D,L-beta-(1-naphthyl)alanine affected hepatic nuclei (binding and enzyme levels), it did not stimulate nucleocytoplasmic translocation of mRNA and concomitant protein synthesis, as did L-tryptophan.
Sidransky
H
H
Department of Pathology, George Washington University Medical Center, Washington, D.C. 20037.
Verney
E
E
Kurl
R
R
D000409:Alanine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D005260:Female; D005944:Glucosamine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D043583:Nucleoside-Triphosphatase; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism*; D011132:Polyribosomes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D014364:Tryptophan / Q000378:metabolism / Q000494:pharmacology*
C059031:1-naphthylalanine; D014364:Tryptophan; D011062:Polynucleotide Adenylyltransferase; D010744:Phosphoric Monoester Hydrolases; D043583:Nucleoside-Triphosphatase; D007930:Leucine; D005944:Glucosamine; D000409:Alanine