Rabinovich Y M, Kreinin M O
A.N. Bakh Institute of Biochemistry, U.S.S.R. Academy of Sciences, Moscow.
Biochim Biophys Acta. 1991 Jun 13;1089(2):193-6. doi: 10.1016/0167-4781(91)90007-9.
[35S]Methionine labelled mitochondrial translation products were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) in the presence of 8 M urea. Following fluorography and scanning, the synthesis time of major polypeptides was determined. It was found that: (1) from 9 to 16 min are required to synthesize various complete polypeptides whose size differs by a factor of more than 5. (2) The specific radioactivity of complete polypeptides with electrophoretic mobilities corresponding to 6 kDa, 16 kDa and 31.5 kDa remains constant during the first 10 min of labelling and attains its final value only after a certain lag-period. (3) In the electrophoretic pattern at least two bands (6.3 kDa and 7.2 kDa) among other bands are nascent, and they accumulate in amounts comparable with that of the complete ones. These data are in agreement with the model of non-uniform elongation rate with a sharp delay (pause) during translation of internal mRNA regions.
在8M尿素存在的情况下，通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）分离[35S]甲硫氨酸标记的线粒体翻译产物。经过荧光显影和扫描后，确定了主要多肽的合成时间。结果发现：（1）合成大小相差超过5倍的各种完整多肽需要9到16分钟。（2）电泳迁移率对应于6kDa、16kDa和31.5kDa的完整多肽的比放射性在标记的前10分钟内保持恒定，并且仅在一定的延迟期后达到其最终值。（3）在电泳图谱中，除其他条带外，至少有两条条带（6.3kDa和7.2kDa）是新生的，它们的积累量与完整条带相当。这些数据与内部mRNA区域翻译过程中伸长率不均匀且有急剧延迟（暂停）的模型一致。
