Secretion granules of the rabbit parotid. Selective removal of secretory contaminants from granule membranes.
Secretion granules of the rabbit parotid. Selective removal of secretory contaminants from granule membranes.
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DOI：
10.1083/jcb.76.2.323
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发表时间：
1978-02
期刊：
影响因子：
--
通讯作者：
Palade GE
中科院分区：
文献类型：
--
作者：
Castle JD;Palade GE
从兔腮腺分离的分泌颗粒中获得的膜亚级分已被证明被残留的分泌蛋白污染，估计水平占其总蛋白的 25-30%。在本研究中，通过改进的混合实验以及通过从膜和内容物亚级分的凝胶中回收的特定多肽的比较肽图谱鉴定了额外的污染物。这种污染物与膜亚级分的主要成分（摩尔重量大约为 40,000）（并且可能包含大部分成分）共电泳。通过在 0.3 M Na2SO4 存在下用低浓度皂苷处理膜，可以在很大程度上去除污染多肽。尽管这种处理破坏了颗粒膜的典型双层结构，但它似乎不会导致其磷脂或真正的膜蛋白解离。
A membrane subfraction obtained from secretion granules isolated from rabbit parotid has been shown to be contaminated by residual secretory proteins to an estimated level of 25-30% of its total protein. In the present study an additional contaminant has been identified by improved mixing experiments and by comparative peptide mapping of specific polypeptides recovered from gels of membrane and content subfractions. This contaminant coelectrophoresis with (and probably comprises the bulk of) the majority component of the membrane subfraction (mol wt approximately 40,000). The contaminating polypeptides can be removed to a large extent by treating the membranes with low concentrations of saponin in the presence of 0.3 M Na2SO4. Although this treatment disrupts the typical bilayer structure of the granule membrane, it does not appear to cause dissociation of its phospholipids or bona fide membrane proteins.