Nygård O, Hultin T
Chem Biol Interact. 1978 Feb;20(2):149-61. doi: 10.1016/0009-2797(78)90049-2.
Partially purified polypeptide chain initiation factors were prepared from the 0.5 M KCl wash of rat liver microsomes. Their activities in connection with dimethylnitrosamine (DMNA)-induced inhibition of protein synthesis were studied by use of the following reactions: (1) poly(U)-directed binding of Phe-tRNA to ribosomes, (2) formation of a GTP-dependent ternary initiation complex with Met-tRNAf, (3) binding of Met-tRNAf to 40-S ribosomal subunits, (4) assembly of a Met-tRNAf containing 80-S ribosomal initiation complex and (5) ribosome-dependent GTPase activity. The inhibition of protein synthesis with DMNA was not associated with a loss of factor activity in any of these reactions. In the binding of Met-tRNAf to 40-S subunits there was a noticeable increase, probably related to the stability of the resulting complex. The Met-tRNA deacylase activity was also increased.
部分纯化的多肽链起始因子是从大鼠肝脏微粒体的0.5M KCl洗涤液中制备的。通过以下反应研究了它们与二甲基亚硝胺（DMNA）诱导的蛋白质合成抑制相关的活性：（1）聚（U）指导的苯丙氨酰-tRNA与核糖体的结合，（2）与甲硫氨酰-tRNAf形成依赖GTP的三元起始复合物，（3）甲硫氨酰-tRNAf与40-S核糖体亚基的结合，（4）包含80-S核糖体起始复合物的甲硫氨酰-tRNAf的组装，以及（5）核糖体依赖性GTP酶活性。DMNA对蛋白质合成的抑制与这些反应中任何一种因子活性的丧失均无关。在甲硫氨酰-tRNAf与40-S亚基的结合中，有明显增加，这可能与所形成复合物的稳定性有关。甲硫氨酰-tRNA脱酰酶活性也增加了。
