NMR structure and binding of esculentin-1a (1-21)NH2 and its diastereomer to lipopolysaccharide: Correlation with biological functions
NMR structure and binding of esculentin-1a (1-21)NH2 and its diastereomer to lipopolysaccharide: Correlation with biological functions
复制标题
DOI：
10.1016/j.bbamem.2015.12.027
复制
发表时间：
2016-04-01
影响因子：
3.4
通讯作者：
Bhunia, Anirban
中科院分区：
文献类型：
--
作者：
Ghosh, Anirban;Bera, Swapna;Bhunia, Anirban
最近发现蛙皮肤衍生的抗微生物肽esculentin-1a（1-21）NH 2 [ESC（1-21）]及其非对映体ESC（1-21）-1c（在位置14和17处含有两个D-氨基酸）中和铜绿假单胞菌脂多糖（LPS）的毒性作用，尽管程度不同。在这里，我们研究了这两种肽的三维结构与铜绿假单胞菌LPS复合物，通过转移核Overhauser效应光谱。NOE峰的缺乏表明两种肽在水溶液中均采用无规卷曲结构。而在LPS胶束中，ESC（1-21）呈两亲性螺旋构象，5个碱性赖氨酸残基形成亲水性簇。相比之下，非对映体仅在N-末端区域保持α螺旋构象，而C-末端部分是相当灵活的。等温滴定量热法（ITC）表明，ESC（1-21）与LPS的相互作用是一个放热过程，其解离常数约为4 μ M。相比之下，ESC（1-21）-1c对LPS胶束的结合亲和力几乎弱8倍。此外，STD NMR数据支持的对接分析已经确定了那些负责肽的结合LPS胶束的氨基酸残基。总体而言，数据提供了重要的机制的见解与LPS的相互作用的esculentin-derived肽和不同的抗内毒素活性的原因。这些数据也可能有助于进一步设计具有抗菌特性的更有效的抗菌肽，这是非常需要的，以克服广泛的concem可用的抗感染剂。(C)2015爱思唯尔B. V.保留所有权利。
The frog skin-derived antimicrobial peptide esculentin-1a(1-21)NH2 [Esc(1-21)], and its diastereomer Esc(1-21)-1c (containing two D-amino acids at positions 14 and 17), have been recently found to neutralize the toxic effect of Pseudomonas aeruginosa lipopolysaccharide (LPS), although to different extents. Here, we studied the three-dimensional structure of both peptides in complex with P. aeruginosa LPS, by transferred nuclear Overhauser effect spectroscopy. Lack of NOE peaks revealed that both the peptides adopted a random coil structure in aqueous solution. However, Esc(1-21) adopted an amphipathic helical conformation in LPS micelles with 5 basic Lys residues forming a hydrophilic cluster. In comparison, the diastereomer maintained an alpha helical conformation only at the N-terminal region, whereas the C-terminal portion was quite flexible. Isothermal titration calorimetry (ITC) revealed that the interaction of Esc(1-21) with LPS is an exothermic process associated with a dissociation constant of similar to 4 mu M. In contrast, Esc(1-21)-1c had almost 8 times weaker binding affinity to LPS micelles. Moreover, STD NMR data supported by docking analysis have identified those amino acid residues responsible for the peptide's binding to LPS micelles.Overall, the data provide important mechanistic insights on the interaction of esculentin-derived peptides with LPS and the reason for their different anti-endotoxin activity. These data might also assist to further design more potent antimicrobial peptides with antisepsis properties, which are highly needed to overcome the widespread concem of the available anti-infective agents. (C) 2015 Elsevier B.V. All rights reserved.