Enhancing the membrane activity of Piscidin 1 through peptide metallation and the presence of oxidized lipid species: Implications for the unification of host defense mechanisms at lipid membranes
Enhancing the membrane activity of Piscidin 1 through peptide metallation and the presence of oxidized lipid species: Implications for the unification of host defense mechanisms at lipid membranes
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通过肽金属化和氧化脂质种类的存在增强 Piscidin 1 的膜活性：对脂质膜宿主防御机制统一的影响
DOI：
10.1016/j.bbamem.2020.183236
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Cotten, Myriam L.
中科院分区：
文献类型：
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作者：
Paredes, Steven D.;Kim, Sarah;Rooney, Mary T.;Greenwood, Alexander I.;Hristova, Kalina;Cotten, Myriam L.
Piscidins是来自鱼类的宿主防御肽（hdp），具有抗菌、抗病毒、抗癌、抗炎和伤口愈合的特性。它们特别富含组氨酸，并且由于在3位存在一个保守的组氨酸而含有氨基末端铜镍（ATCUN）结合基序。金属化降低了它们的总电荷，并为自由基的形成提供了氧化还原中心，自由基可以将不饱和脂肪酸（UFAs）转化为破坏膜稳定的氧化磷脂（OxPLs）。在这里，我们专注于P1，一种特别具有膜活性的异构体，并研究金属化它和使OxPL可用如何影响它的膜活性。首先，我们通过染料泄漏实验量化了载脂蛋白P1和全脂蛋白P1在模型膜上的渗透性，模型膜含有固定比例的阴离子磷脂酰甘油（PG）和两性离子磷脂酰胆碱（PC），但含有不同数量的Aldo-PC，一种由几种ufa降解产生的OxPL。值得注意的是，金属化P1在每个脂质系统中增加了五倍的膜溶解。相反，使Aldo-PC可用，可使每个肽形式的渗透性提高两倍。其次，我们通过cd监测滴定证明，在PC/PG和PC/PG/Aldo-PC中肽-膜相互作用的强度是相似的。因此，肽诱导的膜活性被肽的固有特性（例如，与金属化相关的电荷和结构变化）和双分子层（例如，由于氧化导致的sn-2链逆转）所增强。第三，我们使用定向样品15n固态核磁共振显示，P1的螺旋部分平行于两种脂质体系的双层表面。31P核磁共振实验表明，在PC/PG中，载子态和全态都更容易与PC相互作用。然而，Aldo-PC的存在使得全-而非载脂蛋白态对PG更具特异性。因此，当P1被金属化和OxPL存在时，P1的破膜作用及其对致病细胞膜表面阴离子脂质的特异性同时得到优化。总的来说，这项研究加深了我们对OxPLs如何影响肽-脂质相互作用以及宿主防御金属肽如何帮助整合抗菌药物作用的认识。
Piscidins are host-defense peptides (HDPs) from fish that exhibit antimicrobial, antiviral, anti-cancer, anti-inflammatory, and wound-healing properties. They are distinctively rich in histidine and contain an amino terminal copper and nickel (ATCUN) binding motif due to the presence of a conserved histidine at position 3. Metallation lowers their total charge and provides a redox center for the formation of radicals that can convert unsaturated fatty acids (UFAs) into membrane-destabilizing oxidized phospholipids (OxPLs). Here, we focus on P1, a particularly membrane-active isoform, and investigate how metallating it and making OxPL available influence its membrane activity. First, we quantify through dye leakage experiments the permeabilization of the apo- and holo-forms of P1 on model membranes containing a fixed ratio of anionic phosphatidylglycerol (PG) and zwitterionic phosphatidylcholine (PC) but varying amounts of Aldo-PC, an OxPL derived from the degradation of several UFAs. Remarkably, metallating P1 increases membranolysis by a factor of five in each lipid system. Conversely, making Aldo-PC available improves permeabilization by a factor of two for each peptide form. Second, we demonstrate through CD-monitored titrations that the strength of the peptide-membrane interactions is similar in PC/PG and PC/PG/Aldo-PC. Thus, peptide-induced membrane activity is boosted by properties intrinsic to the peptide (e.g., charge and structural changes associated with metallation) and bilayer (e.g., reversal of sn-2 chain due to oxidation). Third, we show using oriented-sample15N solid-state NMR that the helical portion of P1 lies parallel to the bilayer surface in both lipid systems.31P NMR experiments show that both the apo- and holo-states interact more readily with PC in PC/PG. However, the presence of Aldo-PC renders the holo-, but not the apo-state, more specific to PG. Hence, the membrane disruptive effects of P1 and its specificity for the anionic lipids found on pathogenic cell membrane surfaces are simultaneously optimized when it is metallated and the OxPL is present. Overall, this study deepens our insights into how OxPLs affect peptide-lipid interactions and how host defense metallopeptides could help integrate the effects of antimicrobial agents.