Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau (IIB Sant Pau), Barcelona, Spain; Biochemistry and Molecular Biology Department, Universitat Autònoma de Barcelona, Cerdanyola, Spain.
Cardiovascular Biochemistry Group, Research Institute of the Hospital de Sant Pau (IIB Sant Pau), Barcelona, Spain.
Biochim Biophys Acta Mol Cell Biol Lipids. 2020 Feb;1865(2):158541. doi: 10.1016/j.bbalip.2019.158541. Epub 2019 Oct 28.
Mimetic peptides are promising therapeutic agents for atherosclerosis prevention. A 10-residue class G* peptide from apolipoprotein J (apoJ), namely, D-[113-122]apoJ, possesses anti-inflammatory and anti-atherogenic properties. This prompted us to determine its effect on the aggregation process of low-density lipoprotein (LDL) particles, an early event in the development of atherosclerosis. LDL particles with and without [113-122]apoJ peptide were incubated at 37 °C with sphingomyelinase (SMase) or were left to aggregate spontaneously at room temperature. The aggregation process was analyzed by size-exclusion chromatography (SEC), native gradient gel electrophoresis (GGE), absorbance at 405 nm, dynamic light scattering (DLS), and transmission electronic microscopy (TEM). In addition, circular dichroism was used to determine changes in the secondary structure of apoB, and SDS-PAGE was performed to assess apoB degradation. At an equimolar ratio of [113-122]apoJ peptide to apoB-100, [113-122]apoJ inhibited both SMase-induced or spontaneous LDL aggregation. All methods showed that [113-122]apoJ retarded the progression of SMase-induced LDL aggregation at long incubation times. No effect of [113-122]apoJ on apoB secondary structure was observed. Binding experiments showed that [113-122]apoJ presents low affinity for native LDL but binds readily to LDL during the first stages of aggregation. Laurdan fluorescence experiments showed that mild aggregation of LDL resulted in looser lipid packaging, which was partially prevented by D-[113-122]apoJ. These results demonstrate that [113-122]apoJ peptide prevents SMase-induced LDL aggregation at an equimolar ratio and opens the possibility for the use of this peptide as a therapeutic tool.
模拟肽是预防动脉粥样硬化的有前途的治疗剂。载脂蛋白 J（apoJ）的一种 10 残基 G*肽，即 D-[113-122]apoJ，具有抗炎和抗动脉粥样硬化特性。这促使我们确定其对低密度脂蛋白（LDL）颗粒聚集过程的影响，这是动脉粥样硬化发展的早期事件。载脂蛋白 J 肽存在或不存在 [113-122]apoJ 的 LDL 颗粒在 37°C 下用鞘磷脂酶（SMase）孵育，或在室温下自发聚集。通过尺寸排阻色谱（SEC）、天然梯度凝胶电泳（GGE）、405nm 处的吸光度、动态光散射（DLS）和透射电子显微镜（TEM）分析聚集过程。此外，圆二色性用于确定 apoB 二级结构的变化，SDS-PAGE 用于评估 apoB 降解。在 [113-122]apoJ 肽与 apoB-100 的等摩尔比下，[113-122]apoJ 抑制 SMase 诱导或自发的 LDL 聚集。所有方法均表明，[113-122]apoJ 可延缓 SMase 诱导的 LDL 聚集在长时间孵育时的进展。未观察到 [113-122]apoJ 对 apoB 二级结构的影响。结合实验表明，[113-122]apoJ 对天然 LDL 的亲和力低，但在聚集的早期阶段容易与 LDL 结合。Laurdan 荧光实验表明，LDL 的轻度聚集导致脂质包装更松散，[113-122]apoJ 部分阻止了这种情况。这些结果表明，[113-122]apoJ 肽以等摩尔比阻止 SMase 诱导的 LDL 聚集，并为将该肽用作治疗工具开辟了可能性。
