Detection of prokaryotic signal peptidase in an Escherichia coli membrane fraction: endoproteolytic cleavage of nascent f1 pre-coat protein.
Detection of prokaryotic signal peptidase in an Escherichia coli membrane fraction: endoproteolytic cleavage of nascent f1 pre-coat protein.
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大肠杆菌膜组分中原核信号肽酶的检测：新生 f1 前外壳蛋白的内蛋白水解切割。
DOI：
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发表时间：
1978
影响因子：
11.1
通讯作者：
P. Model
中科院分区：
文献类型：
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作者：
C. N. Chang;G. Blobel;P. Model
从未感染的大肠杆菌中分离出的主要来源于内膜的倒置膜囊泡部分已被证明含有内切蛋白水解活性，其将新生噬菌体f1前外壳蛋白切割成两种可识别的产物。十二烷基硫酸钠/尿素/聚丙烯酰胺凝胶上的电泳迁移率和较大片段的部分氨基末端序列与成熟噬菌体外壳蛋白的那些没有区别。氨基端部分序列分析表明，较小的片段对应于f1前壳蛋白氨基端的“信号肽”。只有在体外合成过程中存在膜级分时才发生裂解，如果在前包被蛋白合成完成后加入，则未观察到裂解。当膜部分与非离子洗涤剂Nikkol一起存在时，切割反应被强烈刺激。这些结果是一致的，并讨论了信号假说。
An inverted membrane vesicle fraction isolated from uninfected Escherichia coli and largely derived from the inner membrane has been shown to contain an endoproteolytic activity that cleaves nascent bacteriophage f1 pre-coat protein into two identifiable products. The electrophoretic mobility on sodium dodecyl sulfate/urea/polyacrylamide gels and the partial amino-terminal sequence of the larger fragment were indistinguishable from those of the mature phage coat protein. Partial amino-terminal sequence analysis showed that the smaller fragment corresponds to the amino-terminal "signal peptide" of f1 pre-coat protein. Cleavage occurred only if the membrane fraction was present during in vitro synthesis, and was not observed if it was added after completion of pre-coat protein synthesis. The cleavage reaction was strongly stimulated when the membrane fraction was present together with the nonionic detergent Nikkol. These results are consistent with and discussed in terms of the signal hyothesis.