Sviridov Denis, Dasseux Amaury, Reimund Mart, Pryor Milton, Drake Steven K, Jarin Zack, Wolska Anna, Pastor Richard W, Remaley Alan T
Laboratory of Lipoprotein Metabolism, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States.
National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States.
Front Cardiovasc Med. 2023 Jul 21;10:1223920. doi: 10.3389/fcvm.2023.1223920. eCollection 2023.
Defects in lipolysis can lead to hypertriglyceridemia, which can trigger acute pancreatitis and is also associated with cardiovascular disease. Decreasing plasma triglycerides (TGs) by activating lipoprotein lipase (LPL) with ApoC2 mimetic peptides is a new treatment strategy for hypertriglyceridemia. We recently described a dual ApoC2 mimetic/ApoC3 antagonist peptide called D6PV that effectively lowered TG in several mouse models but has limitations in terms of drug development. The aim of this study was to create the next generation of ApoC2 mimetic peptides.
We employed hydrocarbon staples, as well as select amino acid substitutions, to make short single helical mimetic peptides based on the last helix of ApoC2. Peptides were first tested for their ability to activate LPL and then in hypertriglyceridemia mouse models. All-atom simulations of peptides were performed in a lipid-trilayer model of TG-rich lipoproteins to discern their possible mechanism of action.
We designed a single stapled peptide called SP1 (21 residues), and a double stapled (stitched) peptide called SP2 (21 residues) and its N-terminal acylated analogue, SP2a. The hydrocarbon staples increased the amphipathicity of the peptides and their ability to bind lipids without interfering with LPL activation. Indeed, from all-atom simulations, the conformations of SP1 and SP2a are restrained by the staples and maintains the proper orientation of the LPL activation motif, while still allowing their deeper insertion into the lipid-trilayer model. Intraperitoneal injection of stapled peptides (1-5 umoles/kg) into ApoC2-hypomorphic mice or human ApoC3-transgenic resulted in an 80%-90% reduction in plasma TG within 3 h, similar to the much longer D6PV peptide (41 residues). Other modifications (replacement L-Glu20, L-Glu21 with their D-isomers, N-methylation of Gly19, Met2NorLeu and Ala1alpha-methylAla substitutions, N-terminal octanoylation) were introduced into the SP2a peptide. These changes made SP2a highly resistant to proteolysis against trypsin, pepsin, and Proteinase K, while maintaining similar efficacy in lowering plasma TG in mice.
We describe a new generation of ApoC2 mimetic peptides based on hydron carbon stapling that are at least equally potent to earlier peptides but are much shorter and resistant to proteolysis and could be further developed into a new therapy for hypertriglyceridemia.
脂肪分解缺陷可导致高甘油三酯血症，进而引发急性胰腺炎，还与心血管疾病相关。通过载脂蛋白C2模拟肽激活脂蛋白脂肪酶（LPL）来降低血浆甘油三酯（TGs）是治疗高甘油三酯血症的一种新策略。我们最近描述了一种名为D6PV的双功能载脂蛋白C2模拟/载脂蛋白C3拮抗剂肽，它在几种小鼠模型中能有效降低TG，但在药物开发方面存在局限性。本研究的目的是创制新一代的载脂蛋白C2模拟肽。
我们采用烃链订书钉以及特定的氨基酸替换，基于载脂蛋白C2的最后一个螺旋结构制备短的单螺旋模拟肽。首先测试这些肽激活LPL的能力，然后在高甘油三酯血症小鼠模型中进行测试。在富含TG的脂蛋白脂质双层模型中对肽进行全原子模拟，以探究其可能的作用机制。
我们设计了一种名为SP1的单链订书肽（21个残基）、一种名为SP2的双链订书（缝合）肽（21个残基）及其N端酰化类似物SP2a。烃链订书钉增加了肽的两亲性及其结合脂质的能力，同时不干扰LPL的激活。实际上，从全原子模拟结果来看，SP1和SP2a的构象受订书钉限制，并保持LPL激活基序的正确取向，同时仍能使其更深地插入脂质双层模型。向载脂蛋白C2低表达小鼠或人载脂蛋白C3转基因小鼠腹腔注射订书肽（1 - 5微摩尔/千克），3小时内血浆TG降低80% - 90%，这与长得多的D6PV肽（41个残基）效果相似。在SP2a肽中引入了其他修饰（用D - 异构体替换L - Glu20、L - Glu21，对Gly19进行N - 甲基化，将Met2替换为正亮氨酸，将Ala1替换为α - 甲基丙氨酸，N端辛酰化）。这些改变使SP2a对胰蛋白酶、胃蛋白酶和蛋白酶K具有高度的抗蛋白水解能力，同时在降低小鼠血浆TG方面保持相似的功效。
我们描述了基于烃链订书技术的新一代载脂蛋白C2模拟肽，它们至少与早期的肽具有同等效力，但更短且抗蛋白水解，有望进一步开发成为治疗高甘油三酯血症的新疗法。
