Mitra R S, Bartoov B, Monahan J, Freeman K B
Biochem J. 1972 Aug;128(5):1033-41. doi: 10.1042/bj1281033.
Mitochondrial ribosomal RNA species from mouse L cells, rat liver, rat hepatoma, hamster BHK-21 cells and human KB cells were examined by electrophoresis on polyacrylamide-agarose gels and sedimentation in sucrose density gradients. The S(E) (electrophoretic mobility) and S values of mitochondrial rRNA of all species were highly dependent on temperature and ionic strength of the medium; the S(E) values increased and the S values decreased with an increase in temperature at a low ionic strength. At an ionic strength of 0.3 at 23-25 degrees C or an ionic strength of 0.01 at 3-4 degrees C the S and S(E) values were almost the same being about 16.2-18.0 and 12.3-13.6 for human and mouse mitochondrial rRNA. The molecular weights under these conditions were calculated to be 3.8x10(5)-4.3x10(5) and 5.9x10(5)-6.8x10(5), depending on the technique used. At 25 degrees C in buffers of low ionic strength mouse mitochondrial rRNA species had a lower electrophoretic mobility than those of human and hamster. Under these conditions the smaller mitochondrial rRNA species of hamster had a lower electrophoretic mobility than that of human but the larger component had an identical mobility. Mouse and rat mitochondrial rRNA species had identical electrophoretic mobilities. Complex differences between human and mouse mitochondrial rRNA species were observed on sedimentation in sucrose density gradients under various conditions of temperature and ionic strength. Mouse L-cell mitochondrial rRNA was eluted after cytoplasmic rRNA on a column of methylated albumin-kieselguhr.
通过在聚丙烯酰胺 - 琼脂糖凝胶上进行电泳以及在蔗糖密度梯度中沉降，对来自小鼠L细胞、大鼠肝脏、大鼠肝癌、仓鼠BHK - 21细胞和人KB细胞的线粒体核糖体RNA种类进行了检测。所有物种线粒体rRNA的S(E)（电泳迁移率）和S值高度依赖于培养基的温度和离子强度；在低离子强度下，随着温度升高，S(E)值增加而S值降低。在23 - 25℃时离子强度为0.3或在3 - 4℃时离子强度为0.01的条件下，人和小鼠线粒体rRNA的S和S(E)值几乎相同，分别约为16.2 - 18.0和12.3 - 13.6。根据所使用的技术，在这些条件下计算出的分子量分别为3.8×10⁵ - 4.3×10⁵和5.9×10⁵ - 6.8×10⁵。在25℃的低离子强度缓冲液中，小鼠线粒体rRNA种类的电泳迁移率低于人和仓鼠的。在这些条件下，仓鼠较小的线粒体rRNA种类的电泳迁移率低于人，但较大的组分具有相同的迁移率。小鼠和大鼠线粒体rRNA种类具有相同的电泳迁移率。在不同温度和离子强度条件下于蔗糖密度梯度中沉降时，观察到人和小鼠线粒体rRNA种类之间存在复杂差异。小鼠L细胞线粒体rRNA在甲基化白蛋白 - 硅藻土柱上比细胞质rRNA后洗脱。
