NMR studies of aurein 1.2 analogs
NMR studies of aurein 1.2 analogs
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DOI：
10.1016/j.bbamem.2006.03.032
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发表时间：
2006-09-01
影响因子：
3.4
通讯作者：
Wang, Guangshun
中科院分区：
文献类型：
--
作者：
Li, Xia;Li, Yifeng;Wang, Guangshun
Aurein 1.2 是一种从澳大利亚青蛙中分离出来的抗菌和抗癌肽。为了加深我们对作用机制的理解，设计了两个系列的肽。第一个系列包括细菌葡萄糖特异性酶 IIA 的 N 端膜锚、aurein 1.2 和新鉴定的来自人 LL-37 (LLAA) 的 aurein 1.2 类似物。抗菌活性的顺序是 LLAA > aurein 1.2 >> 膜锚（无活性）。洗涤剂胶束中 LLAA 的结构通过 H-1 NMR 光谱测定，包括通过天然丰度 C-13(α)、C-13(β) 和 N-15 化学位移进行结构精修。 3D 结构的疏水表面积与肽在反相 HPLC 柱上的保留时间相关。与金黄色素 1.2 相比，LLAA 的较高活性归因于额外的阳离子残基增强了膜扰动电位。第二个肽系列是通过将 aurein 1.2 的 C 末端苯丙氨酸 (F13) 更改为苯甘氨酸或色氨酸而创建的。相对于 F13，突变体中芳香环距离肽主链更近或更远的位置被认为会导致活性下降。具有独特化学位移的苯甘氨酸可能是抗菌肽构效关系研究的有用核磁共振探针。为了促进未来 NMR 研究的潜在用途，使用合成肽 GGXGG 测量了苯基甘氨酸 (X) 的随机螺旋化学位移。所有肽中的苯丙氨酸芳香族都渗透到脂质头基下方 2-5 埃处，对于膜靶向至关重要，如分子间肽-脂质 NOE 模式所示。 (c) 2006 Elsevier B.V. 保留所有权利。
Aurein 1.2 is an antimicrobial and anticancer peptide isolated from an Australian frog. To improve our understanding of the mechanism of action, two series of peptides were designed. The first series includes the N-terminal membrane anchor of bacterial glucose-specific enzyme IIA, aurein 1.2, and a newly identified aurein 1.2 analog from human LL-37 (LLAA). The order of antibacterial activity is LLAA > aurein 1.2 >> the membrane anchor (inactive). The structure of LLAA in detergent micelles was determined by H-1 NMR spectroscopy, including structural refinement by natural abundance C-13(alpha),C-13(beta), and N-15 chemical shifts. The hydrophobic surface area of the 3D structure is related to the retention time of the peptide on a reverse-phase HPLC column. The higher activity of LLAA compared to aurein 1.2 was attributed to additional cationic residues that enhance the membrane perturbation potential. The second peptide series was created by changing the C-terminal phenylalanine (F13) of aurein 1.2 to either phenylglycine or tryptophan. A closer or further location of the aromatic rings to the peptide backbone in the mutants relative to F13 is proposed to cause a drop in activity. Phenylglycine with unique chemical shifts may be a useful NMR probe for structure-activity relationship studies of antimicrobial peptides. To facilitate potential future use for NMR studies, random-coil chemical shifts for phenylglycine (X) were measured using the synthetic peptide GGXGG. Aromatic kings of phenylalanines in all the peptides penetrated 2-5 angstrom below the lipid head group and are essential for membrane targeting as illustrated by intermolecular peptide-lipid NOE patterns. (c) 2006 Elsevier B.V. All rights reserved.