Sidransky H, Verney E, Kurl R
Department of Pathology, George Washington University Medical Center, Washington, D.C. 20037.
J Nutr. 1990 Oct;120(10):1157-62. doi: 10.1093/jn/120.10.1157.
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.
早期研究报道，给予L-色氨酸可增加大鼠肝脏中的多核糖体聚集、蛋白质合成以及细胞质多聚腺苷酸（poly(A)）mRNA水平。本研究关注的是L-色氨酸类似物D,L-β-(1-萘基)丙氨酸的作用，并与L-色氨酸的作用进行比较。D,L-β-(1-萘基)丙氨酸和L-色氨酸均与L-色氨酸受体蛋白结合，并增加肝细胞核的多聚腺苷酸聚合酶和核苷三磷酸酶活性。然而，只有L-色氨酸与大鼠肝脏中标记核RNA的释放增加（体外）、蛋白质合成增加、多核糖体聚集增加以及糖基化（[14C]葡萄糖胺掺入蛋白质）有关。这些结果表明，尽管D,L-β-(1-萘基)丙氨酸影响肝细胞核（结合和酶水平），但它并不像L-色氨酸那样刺激mRNA的核质转运及伴随的蛋白质合成。
