Tuning of a Membrane-Perforating Antimicrobial Peptide to Selectively Target Membranes of Different Lipid Composition
Tuning of a Membrane-Perforating Antimicrobial Peptide to Selectively Target Membranes of Different Lipid Composition
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DOI：
10.1007/s00232-021-00174-1
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发表时间：
2021-02-10
影响因子：
2.4
通讯作者：
Ulmschneider, Jakob P.
中科院分区：
文献类型：
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作者：
Chen, Charles H.;Starr, Charles G.;Ulmschneider, Jakob P.
由于缺乏简单的序列-结构-功能关系和设计规则，设计抗菌肽作为药物的使用受到阻碍。可能的原因是许多这些多肽通过高度无序的、异质的机制渗透膜，形成没有明确的三级或二级结构的聚集体。我们建议将高通量文库筛选与原子计算机模拟相结合，通过将先前开发的一般成孔肽调整为不同脂质类型的选择性成孔肽，可以成功地解决这一挑战。基于LDKA模板设计了包含2916个肽段的文库。利用高通量正交囊泡渗漏法合成和筛选文库肽。不同大小的染料被包裹在不同脂质组成的囊泡中，同时筛选孔径和对负电荷和中性脂质膜的亲和力。从这个筛选中，选择了9种具有独特活性的不同的LDKA变体，对其进行了测序、合成和表征。尽管这些肽的序列发生了微小的变化，但它们都具有独特的功能特性，可以形成小孔隙或大孔隙，并对中性或阴离子脂质双分子层具有选择性。长尺度、无偏原子分子动力学（MD）模拟直接显示，这些肽不是刚性的、定义良好的孔隙，而是可以形成大量的功能动态和异质聚集体，受到单一突变的强烈影响。仅从序列预测在给定环境中聚集和组装的倾向是预测膜渗透功能的关键。
The use of designed antimicrobial peptides as drugs has been impeded by the absence of simple sequence-structure-function relationships and design rules. The likely cause is that many of these peptides permeabilize membranes via highly disordered, heterogeneous mechanisms, forming aggregates without well-defined tertiary or secondary structure. We suggest that the combination of high-throughput library screening with atomistic computer simulations can successfully address this challenge by tuning a previously developed general pore-forming peptide into a selective pore-former for different lipid types. A library of 2916 peptides was designed based on the LDKA template. The library peptides were synthesized and screened using a high-throughput orthogonal vesicle leakage assay. Dyes of different sizes were entrapped inside vesicles with varying lipid composition to simultaneously screen for both pore size and affinity for negatively charged and neutral lipid membranes. From this screen, nine different LDKA variants that have unique activity were selected, sequenced, synthesized, and characterized. Despite the minor sequence changes, each of these peptides has unique functional properties, forming either small or large pores and being selective for either neutral or anionic lipid bilayers. Long-scale, unbiased atomistic molecular dynamics (MD) simulations directly reveal that rather than rigid, well-defined pores, these peptides can form a large repertoire of functional dynamic and heterogeneous aggregates, strongly affected by single mutations. Predicting the propensity to aggregate and assemble in a given environment from sequence alone holds the key to functional prediction of membrane permeabilization.