Effects of cation binding to hydrophobic helical peptides on orientation, aggregation, and ion-channel activity in phospholipid bilayer membranes
Effects of cation binding to hydrophobic helical peptides on orientation, aggregation, and ion-channel activity in phospholipid bilayer membranes
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阳离子与疏水性螺旋肽的结合对磷脂双层膜中的取向、聚集和离子通道活性的影响
DOI：
10.1039/p19930003011
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Y. Imanishi
中科院分区：
文献类型：
--
作者：
K. Otoda;S. Kimura;Y. Imanishi
本文研究了阳离子与α-螺旋肽C端结合对磷脂双层膜构象、取向、聚集和离子通道活性的影响。已经合成了在C-末端区域具有冠醚单元的疏水螺旋肽Boc-[Ala-Aib]n-Ala-Cr（Cr表示苯并-18-冠-6单元，n= 4，8），以及在N-末端区域具有蒽基基团的疏水螺旋肽Boc-Ser（Ant）-[Ala-Aib]n-Ala-Cr（Ant表示蒽基甲基基团，n= 4，8）。由于螺旋大偶极子的负极与阳离子的相互作用，与K+络合后，肽的螺旋含量增加。将肽掺入磷脂双层膜中，并以跨膜取向聚集。Boc-[Ala-Aib]4-Ala-Cr在双层膜中具有离子通道活性。活性高于Boc-[Ala-Aib]4-OMe，因为冠醚单元作为通道的阳离子结合位点起作用。特别是在Rb+和Cs+的存在下，由于形成了一个E-type冠/阳离子络合物的冠肽的聚集促进。因为这个原因Boc-[Ala-Aib]4-Ala-Cr在Cs+存在下比在K+存在下显示出更高的通道样活性。另一方面，Boc-[Ala-Aib]4-Ala-Cr在掺入到双层膜中时聚集，并显示出离子通道样活性。在任何一种肽中，冠醚单元与疏水螺旋肽的连接通过促进跨膜取向的聚集来增强其通道形成能力。
Effects of cation binding to the C-terminal of α-helical peptides on conformation, orientation, aggregation, and ion-channel activity in a phospholipid bilayer membrane have been studied. The hydrophobic helical peptides having a crown ether unit at the C-terminal region, Boc-[Ala-Aib]n-Ala-Cr (Cr represents a benzo-18-crown-6 unit, n= 4,8), and an anthryl group at the N-terminal region as well, Boc-Ser(Ant)-[Ala-Aib]n-Ala-Cr (Ant represents an anthrylmethyl group, n= 4,8), have been synthesized. The helix content of the peptides increased upon complexation with K+ because of interaction of the negative pole of the helic macrodipole with the cation. The peptides were incorporated into a phospholipid bilayer membrane, and aggregated taking a transmembrane orientation. Boc-[Ala-Aib]4-Ala-Cr showed an ion-channel-like activity in a bilayer membrane. The activity was higher than that of Boc-[Ala-Aib]4-OMe, since the crown ether unit functions as a cation-binding site of the channel. The aggregation of the crown-peptides was promoted especially in the presence of Rb+ and Cs+ due to formation of a sandwich-type crown/cation complex. For this reason. Boc-[Ala-Aib]4-Ala-Cr showed a higher channel-like activity in the presence of Cs+ than K+ On the other hand, Boc-[Ala-Aib]4-Ala-Cr aggregated upon incorporation into a bilayer membrane, and showed an ion-channel-like activity. In any one of the peptides, the connection of a crown ether unit to the hydrophobic helical peptide augmented its channel-forming ability by facilitating aggregation with a transmembrane orientation.
使用 13C NMR 测定阿拉甲辛的分子动力学：对电压依赖性通道门控机制的影响。
影响因子：
2.9
作者：
Kelsh,LP;Ellena,JF;Cafiso,DS
通讯作者：
Cafiso,DS