EXCHANGE OF INDIVIDUAL RIBOSOMAL-PROTEINS BETWEEN RIBOSOMES AS STUDIED BY HEAVY ISOTOPE-TRANSFER EXPERIMENTS
EXCHANGE OF INDIVIDUAL RIBOSOMAL-PROTEINS BETWEEN RIBOSOMES AS STUDIED BY HEAVY ISOTOPE-TRANSFER EXPERIMENTS
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DOI：
10.1007/bf00455113
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发表时间：
1977-01-01
期刊：
影响因子：
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通讯作者：
VANDUIN, J
中科院分区：
文献类型：
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作者：
SUBRAMANIAN, AR;VANDUIN, J
使用重同位素转移方法检查在细胞生长期间个体核糖体蛋白是否在体内在机器人之间进行交换。大肠杆菌首先在[3 H]亮氨酸存在下在重同位素培养基中生长，然后转移到正常培养基中并允许在[14 C]亮氨酸存在下生长1代。通过沉降分离存在于这样的细胞中的重和轻核糖体，并且通过二维凝胶电泳解析核糖体蛋白。将单个蛋白质在O2中燃烧，并测定其[3 H]和[14 C]标记的含量。结果表明，绝大多数E.大肠杆菌在细胞生长过程中不进行交换。在不同转移实验中交换至不同水平的蛋白质为S1、S2、L7/L12、L9、L10和L33。除L9外，所有这些细胞在对照实验中交换至相同水平，在对照实验中，将单独生长的重细胞和轻细胞混合并处理。因此，这些蛋白质在细胞破裂和核糖体分离期间进行交换。与对照相比，蛋白质L9在转移实验中始终显示出明显更大的交换，表明其可以在体内交换。
Whether the individual ribosomal proteins undergo exchange between robosomes in vivo during cell growth was examined using heavy isotope transfer methodology. Escherichia coli was grown first in a heavy isotope medium in the presence of [3H] leucine and then transferred to normal medium and allowed to grow for 1 generation in the presence of [14C] leucine. The heavy and light ribosomes that were present in such cells were separated by sedimentation and the ribosomal proteins resolved by 2-dimensional gel electrophoresis. The individual proteins were burnt in O2 and their contents of [3H] and [14C] labels determined. The analysis of the data showed that the great majority of the ribosomal proteins of E. coli does not undergo exchange during cell growth. Proteins which exchanged to varying levels in different transfer experiments were S1, S2, L7/L12, L9, L10 and L33. All of them except L9 exchanged to the same levels in control experiments in which separately grown heavy and light cells were mixed and processed. These proteins therefore undergo exchange during cell breakage and ribosome isolation. Protein L9 consistently showed appreciably greater exchange in transfer experiments as compared to the controls suggesting that it may exchange in vivo.