突触体蛋白在 P2 和菲可（Ficoll）纯化级分中的合成。

Synaptosomal protein synthesis in P2 and Ficoll purified fractions.

机构信息

Department of Biological Sciences, University of Naples 'Federico II', Via Mezzocannone 8, Naples 80134, Italy.

出版信息

J Neurosci Methods. 2012 Jan 30;203(2):335-7. doi: 10.1016/j.jneumeth.2011.10.007. Epub 2011 Oct 15.

DOI:10.1016/j.jneumeth.2011.10.007

PMID:22020116

Abstract

Cytoplasmic protein synthesis of brain synaptosomes has generally been determined in the Ficoll purified fraction which contains fewer contaminating mitochondria, microsomes and myelin fragments than the parent P2 fraction. Using a highly selective assay of this activity we have compared the total translation activity and the specific activity of the proteins synthesized by either fraction in control rats and in rats trained for a two-way active avoidance task. In control rats the specific activity remained essentially the same in both fractions but in trained rats the value of the Ficoll fraction was markedly lower (38.5%) than in the P2 fraction. Furthermore, the total translation activity of the Ficoll fraction was 30% lower than in the P2 fraction in control rats and 62% lower in trained rats. These decrements indicate that a large proportion of active synaptosomes present in the P2 fraction is not recovered in the Ficoll fraction, notably in rats undergoing plastic brain changes. We conclude that cytoplasmic protein synthesis of brain synaptosomes is better preserved in the P2 fraction.

摘要

脑突触体的细胞质蛋白合成通常在菲可（Ficoll）纯化的部分中进行，该部分比原始 P2 部分含有更少的污染线粒体、微粒体和髓磷脂片段。使用这种活性的高度选择性测定方法，我们比较了控制大鼠和经过双向主动回避任务训练的大鼠中两个部分的总翻译活性和合成的蛋白质的比活性。在对照大鼠中，两个部分的比活性基本相同，但在训练大鼠中，菲可（Ficoll）部分的值明显低于 P2 部分（38.5%）。此外，在对照大鼠中，菲可（Ficoll）部分的总翻译活性比 P2 部分低 30%，在训练大鼠中低 62%。这些减少表明，在 P2 部分中存在的大量活跃突触体并未在菲可（Ficoll）部分中回收，特别是在经历大脑可塑性变化的大鼠中。我们得出结论，脑突触体的细胞质蛋白合成在 P2 部分中得到更好的保留。