Roise D, Theiler F, Horvath S J, Tomich J M, Richards J H, Allison D S, Schatz G
Biocenter, University of Basel, Switzerland.
EMBO J. 1988 Mar;7(3):649-53. doi: 10.1002/j.1460-2075.1988.tb02859.x.
We have shown earlier that a mitochondrial presequence peptide can form an amphiphilic helix. However, the importance of amphiphilicity for mitochondrial presequence function became doubtful when an artificial presequence, designed to be non-amphiphilic, proved to be active as a mitochondrial import signal. We now show experimentally that this 'non-amphiphilic' presequence peptide is, in fact, highly amphiphilic as measured by its ability to insert into phospholipid monolayers and to disrupt phospholipid vesicles. This result, and similar tests on three additional artificial presequences (two functionally active and one inactive), revealed that all active presequences were amphiphilic whereas the inactive presequence was non-amphiphilic. One of the active presequence peptides was non-helical in solution and in the presence of detergent micelles. We conclude that amphiphilicity is necessary for mitochondrial presequence function whereas a helical structure may not be essential.
我们之前已经表明，线粒体前导肽可以形成两亲性螺旋。然而，当一个设计为非两亲性的人工前导肽被证明作为线粒体导入信号具有活性时，两亲性对于线粒体前导肽功能的重要性就变得可疑了。我们现在通过实验表明，这种“非两亲性”前导肽实际上具有高度两亲性，这是通过其插入磷脂单层和破坏磷脂囊泡的能力来衡量的。这一结果，以及对另外三种人工前导肽（两种功能活性肽和一种无活性肽）的类似测试表明，所有活性前导肽都是两亲性的，而无活性前导肽是非两亲性的。其中一种活性前导肽在溶液中和存在去污剂胶束的情况下是非螺旋的。我们得出结论，两亲性对于线粒体前导肽功能是必要的，而螺旋结构可能不是必需的。
