Analysis of oxidation level of low-density lipoprotein particles

利用原子力显微镜系统研究了LDL在金属诱导氧化前后的性质。LDL的表面电位随氧化程度的增加而降低。氧化前的电位分布比氧化后的电位分布宽，氧化前后LDL的硬度随氧化程度的增加而降低。氧化前LDL的硬度分布较宽，部分LDL的硬度呈软态，如氧化LDL。凝胶过滤的氧化低密度脂蛋白样品，包括软LDL诱导血小板聚集和增强红细胞的破坏。软LDL可能与心脏疾病有关，LDL的硬度分布不仅可作为评价LDL氧化程度的新工具，而且可作为评价健康状况的新工具。

Properties of LDL before and after metal induced oxidation were investigated by an atomic force microscopy system. Surface potential of the LDL decreased with increasing oxidation degree of the LDL. The distribution of the potential before oxidation was wider than that of the potential after oxidation.Stiffness of the LDL before and after oxidation also decreased with increasing oxidation degree. Distribution of the stiffness of the LDL before oxidation was wide and the stiffness of some LDL particles showed soft such like oxidized LDL. Gel-filtrated sample of oxidized LDL that included the soft LDL induced aggregations of blood platelet and enhance destruction of red blood cells. It is suggested that soft LDL might be related to cardiac disease and that the distribution the stiffness of the LDL might be a novel tool to evaluate not only oxidation degree of the LDL but also to evaluate the degree of the health condition.