ANIONIC PHOSPHOLIPIDS ARE ESSENTIAL FOR ALPHA-HELIX FORMATION OF THE SIGNAL PEPTIDE OF PREPHOE UPON INTERACTION WITH PHOSPHOLIPID-VESICLES
ANIONIC PHOSPHOLIPIDS ARE ESSENTIAL FOR ALPHA-HELIX FORMATION OF THE SIGNAL PEPTIDE OF PREPHOE UPON INTERACTION WITH PHOSPHOLIPID-VESICLES
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DOI：
10.1021/bi00121a014
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发表时间：
1992-02-18
期刊：
影响因子：
2.9
通讯作者：
DEKRUIJFF, B
中科院分区：
文献类型：
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作者：
KELLER, RCA;KILLIAN, JA;DEKRUIJFF, B
使用圆二色性研究了PhoE信号肽与不同类型磷脂的双层的相互作用的构象后果。结果发现，信号肽与二油酰磷脂酰甘油和二油酰磷脂酰丝氨酸的阴离子磷脂囊泡的相互作用导致分别诱导70%和57%的大量α-螺旋结构。在心磷脂囊泡中加入信号肽后，诱导了较少但仍然显著的α-螺旋结构（29%）。相反，没有观察到α-螺旋形成后的信号肽与两性离子二油酰磷脂酰胆碱囊泡的相互作用。在二油酰磷脂酰胆碱与二油酰磷脂酰甘油的双层中，结果表明，在100 mM NaCl的存在下，诱导最大百分比的α-螺旋需要最小量的50%的带负电荷的脂质，而在不存在盐的情况下，需要最小量的35%的带负电荷的脂质。α-螺旋结构的诱导似乎与功能相关，因为在PhoE信号肽的功能较低的类似物PhoE-[Asp-19，20]信号肽中，诱导的α-螺旋比野生型PhoE信号肽少。有人提出，与阴离子磷脂的相互作用是必不可少的功能构象的PhoE信号序列在蛋白质易位。
The conformational consequences of the interaction of the PhoE signal peptide with bilayers of different types of phospholipids was investigated using circular dichroism. It was found that interaction of the signal peptide with anionic phospholipid vesicles of dioleoylphosphatidylglycerol and dioleoylphosphatidylserine results in induction of high amounts of alpha-helical structure of 70% and 57%, respectively. Upon addition of the signal peptide to cardiolipin vesicles, less but still significant alpha-helical structure was induced (29%). In contrast, no alpha-helix formation was observed upon the interaction of the signal peptide with zwitterionic dioleoylphosphatidylcholine vesicles. In bilayers of dioleoylphosphatidylcholine with dioleoylphosphatidylglycerol, it was shown that in the presence of 100 mM NaCl a minimum amount of 50% of negatively charged lipid was required for induction of the maximal percentage of alpha-helix, whereas in the absence of salt a minimum amount of 35% of negatively charged lipid was necessary. Induction of alpha-helix structure appeared to be correlated with functionality, since, in a less functional analogue of the PhoE signal peptide, the PhoE-[Asp-19,20] signal peptide, less alpha-helix was induced than in the wild-type PhoE signal peptide. It is proposed that the interaction with anionic phospholipids is essential for a functional conformation of the PhoE signal sequence during protein translocation.