Fout G S, Medappa K C, Mapoles J E, Rueckert R R
J Biol Chem. 1984 Mar 25;259(6):3639-43.
HeLa cells were made strictly dependent upon polyamine by growth in the presence of alpha-difluoromethylornithine, a specific inhibitor of ornithine decarboxylase. Under these conditions, the specific activity of the cellular polyamine pools eventually equilibrated to that of exogenously supplied [14C]putrescine; however, the process was very slow, requiring half-equilibration times of about 16 h for spermidine and 28 for spermine. Thus, the distribution of radioactivity in individual polyamines became a valid measure of polyamine content only after a continuous 4-day incorporation period. When propagated in polyamine-labeled cells, two picornaviruses were found to incorporate substantially different amounts of polyamine: about 0.6% of the cell pool for human rhinovirus 14 but only 0.04% for poliovirus. This content of polyamine was sufficient to neutralize nearly 27% of the negative charge of the RNA in human rhinovirus 14 but only 1.6% in poliovirus.
通过在鸟氨酸脱羧酶的特异性抑制剂α-二氟甲基鸟氨酸存在下培养，使HeLa细胞严格依赖多胺生长。在这些条件下，细胞多胺池的比活性最终与外源供应的[14C]腐胺达到平衡；然而，这个过程非常缓慢，亚精胺的半平衡时间约为16小时，精胺则为28小时。因此，只有在连续4天的掺入期后，放射性在各个多胺中的分布才成为多胺含量的有效衡量指标。当在多胺标记的细胞中繁殖时，发现两种小核糖核酸病毒掺入的多胺量有很大差异：人鼻病毒14约占细胞池的0.6%，而脊髓灰质炎病毒仅占0.04%。这种多胺含量足以中和人鼻病毒14中近27%的RNA负电荷，但在脊髓灰质炎病毒中仅为1.6%。
