Egberts E, Hackett P B, Traub P
Hoppe Seylers Z Physiol Chem. 1976 Dec;357(12):1179-92.
The effect of mengovirus infection on the protein synthetic capacity of Ehrlich ascites tumor cells cultured in vitro was studied in vivo and in vitro employing postnuclear supernatants prepared at various times post-infection in the absence and in the presence of 1% Triton X-100. The amino acid incorporating activities of extracts obtained in the presence of the detergent were reduced by about 30% compared with the capacities of the corresponding postnuclear supernatants prepared in the absence of Triton X-100; but the course of the activity vs. time curve was not influenced by the detergent. Under the conditions employed, the postnuclear supernatants were unable to reinitiate protein synthesis once elongation of nascent polypeptide chains concomitant with ribosome runoff was completed. After mengovirus infection, a gradual disappearance of polysomes from postnuclear supernatants and a simultaneous accumulation of monosomes was observed. The protein-synthesizing activities of normal and infected cells were inversely proportional to the monosome concentrations of their corresponding extracts. Qualitatively, protein synthesis in intact cells and in postnuclear supernatants responded similarly to mengovirus infection. In both cases an initial reduction of host-specific amino acid incorporation was followed by a burst of viral protein synthesis. However, the two activity vs. time curves showed the following significant differences: 1) The activities of extracts from control cells and from mengovirus-infected cells nearly in the infectious cycle were low compared with the activities observed in vivo. 2) In the middle of the infectious cycle, the peak of viral protein synthesis occurred later and the activity was higher in vitro. 3) Finally, in the late period of the infectious cycle the postnuclear supernatants had considerable protein synthesizing activity, at a time when protein synthesis in vivo was nil.
利用在感染后不同时间制备的核后上清液,在有无1% Triton X - 100存在的情况下,在体内和体外研究了脑心肌炎病毒感染对体外培养的艾氏腹水瘤细胞蛋白质合成能力的影响。与在无Triton X - 100情况下制备的相应核后上清液的能力相比,在去污剂存在下获得的提取物的氨基酸掺入活性降低了约30%;但活性与时间曲线的进程不受去污剂影响。在所采用的条件下,一旦与核糖体流失相伴的新生多肽链延长完成,核后上清液就无法重新启动蛋白质合成。脑心肌炎病毒感染后,观察到核后上清液中多核糖体逐渐消失,同时单核糖体积累。正常细胞和感染细胞的蛋白质合成活性与其相应提取物的单核糖体浓度成反比。定性地说,完整细胞和核后上清液中的蛋白质合成对脑心肌炎病毒感染的反应相似。在这两种情况下,宿主特异性氨基酸掺入首先降低,随后是病毒蛋白质合成的爆发。然而,两条活性与时间曲线显示出以下显著差异:1)与体内观察到的活性相比,对照细胞和处于感染周期近感染期的脑心肌炎病毒感染细胞提取物的活性较低。2)在感染周期中期,病毒蛋白质合成的峰值出现较晚,且体外活性较高。3)最后,在感染周期后期,核后上清液具有相当大的蛋白质合成活性,而此时体内蛋白质合成已不存在。