Orientation and Location of the Cyclotide Kalata B1 in Lipid Bilayers Revealed by Solid-State NMR.
Orientation and Location of the Cyclotide Kalata B1 in Lipid Bilayers Revealed by Solid-State NMR.
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固态核磁共振揭示脂质双层中环肽 Kalata B1 的方向和位置
DOI：
10.1016/j.bpj.2016.12.040
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发表时间：
2017
影响因子：
3.4
通讯作者：
A.S. Ulrich
中科院分区：
文献类型：
--
作者：
S.L. Grage;M.-A. Sani;O. Cheneval;S. Troeira Henriques;C. Schalck;R. Heinzmann;J.S. Mylne;P.K. Mykhailiuk;S. Afonin;I.V. Komarov;F. Separovic;D.J. Craik;A.S. Ulrich
环肽是一种超稳定的富含二硫键的植物环肽。它们的生物物理效应和医学上令人感兴趣的活性与它们的膜结合特性有关，对磷脂酰乙醇胺脂质具有特别高的亲和力。在这项研究中，我们有兴趣了解环肽-膜相互作用的分子细节，特别是关于包埋在脂质双层中时的cyclotide kalata B1 fromOldenlandia affinis的空间取向。我们的实验方法是基于使用固态19 F-NMR的定向双层结合构象限制的氨基酸L-3-（三氟甲基）双环戊二烯-[1.1.1]-1-基甘氨酸作为一个orientation-sensitive 19 F-NMR探针。它与kalata B1骨架支架的刚性连接，以及环肽的明确结构，使我们能够直接从取向敏感的19 F-NMR信号计算膜中的蛋白质排列。kalata B1表面的疏水性和极性残基形成分离良好的补丁，赋予这种环肽具有明显的两亲性。通过核磁共振确定的肽方向表明，这种两亲结构与脂双层的极性/非极性界面非常匹配。在双层的两亲性头基区域的位置被支持由15 N-NMR的均匀标记的蛋白质，并确认使用固态31 P-和2 H-NMR。31 P-NMR弛豫数据表明，在脂质头基动力学的变化引起的kalata B1。在the 2 H-NMR顺序参数配置文件的酰基链的变化表明膜变薄，通常观察到的两亲性肽嵌入附近的极性/非极性双层界面。此外，从19 F-NMR分析，发现两个重要的带电残基，E7和R28，位于赤道。因此，所观察到的位置将有利于假定的E7磷脂酰乙醇胺脂质头基的结合。此外，可以推测，这对侧链可以通过其互补电荷通过静电分子间接触促进kalata B1的寡聚化。
Cyclotides are ultra-stable cyclic disulfide-rich peptides from plants. Their biophysical effects and medically interesting activities are related to their membrane-binding properties, with particularly high affinity for phosphatidylethanolamine lipids. In this study we were interested in understanding the molecular details of cyclotide-membrane interactions, specifically with regard to the spatial orientation of the cyclotide kalata B1 fromOldenlandia affiniswhen embedded in a lipid bilayer. Our experimental approach was based on the use of solid-state19F-NMR of oriented bilayers in conjunction with the conformationally restricted amino acidL-3-(trifluoromethyl)bicyclopent-[1.1.1]-1-ylglycine as an orientation-sensitive19F-NMR probe. Its rigid connection to the kalata B1 backbone scaffold, together with the well-defined structure of the cyclotide, allowed us to calculate the protein alignment in the membrane directly from the orientation-sensitive19F-NMR signal. The hydrophobic and polar residues on the surface of kalata B1 form well-separated patches, endowing this cyclotide with a pronounced amphipathicity. The peptide orientation, as determined by NMR, showed that this amphipathic structure matches the polar/apolar interface of the lipid bilayer very well. A location in the amphiphilic headgroup region of the bilayer was supported by15N-NMR of uniformly labeled protein, and confirmed using solid-state31P- and2H-NMR.31P-NMR relaxation data indicated a change in lipid headgroup dynamics induced by kalata B1. Changes in the2H-NMR order parameter profile of the acyl chains suggest membrane thinning, as typically observed for amphiphilic peptides embedded near the polar/apolar bilayer interface. Furthermore, from the19F-NMR analysis two important charged residues, E7 and R28, were found to be positioned equatorially. The observed location thus would be favorable for the postulated binding of E7 to phosphatidylethanolamine lipid headgroups. Furthermore, it may be speculated that this pair of side chains could promote oligomerization of kalata B1 through electrostatic intermolecular contacts via their complementary charges.
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不饱和度对二油酰磷脂酰乙醇胺基质中磷脂酰胆碱链序的影响。
影响因子：
3.4
作者：
F. Separovic;K. Gawrisch
通讯作者：
K. Gawrisch
影响因子：
6.8
作者：
Torsten H. Walther;A. Ulrich
通讯作者：
Torsten H. Walther;A. Ulrich
环肽插入脂质双层形成膜孔并通过疏水性和磷酸乙醇胺特异性相互作用使膜不稳定*
DOI：
10.1074/jbc.m112.421198
发表时间：
2012
期刊：
The Journal of Biological Chemistry
影响因子：
--
作者：
Conan K. Wang;H. Wacklin;D. Craik
通讯作者：
D. Craik
影响因子：
64.5
作者：
Walther, Torsten H.;Gottselig, Christina;Ulrich, Anne S.
通讯作者：
Ulrich, Anne S.
影响因子：
4.8
作者：
Huang, Yen-Hua;Colgrave, Michelle L.;Craik, David J.
通讯作者：
Craik, David J.