The purpose of this study is to determine whether the nature of the post-translational modifications of the major apolipoproteins of HDL is different for density-distinct subclasses. These subclasses were separated by ultracentrifugation using a novel density-forming solute to yield a high-resolution separation. The serum of two subjects, a control with a normolipidemic profile and a subject with diagnosed cardiovascular disease, was studied. Aliquots of three HDL subclasses were analyzed by MALDI and considerable differences were seen when comparing density-distinct subclasses and also when comparing the two subjects. A detailed analysis of the post-translational modification pattern of apoA-1 shows evidence of considerable protease activity, particularly in the more dense fractions. We conclude that part of the heterogeneity of the population of HDL particles is due to density-dependent protease activity.

中文翻译：

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HDL的UC/MALDI-MS分析；密度依赖性翻译后修饰的证据

本研究的目的是确定 HDL 主要载脂蛋白的翻译后修饰的性质是否与密度不同的亚类不同。这些亚类使用新型密度形成溶质通过超速离心进行分离，以产生高分辨率分离。研究了两个受试者的血清，一个是血脂正常的对照，另一个是被诊断为心血管疾病的受试者。通过 MALDI 分析了三个 HDL 亚类的等分试样，在比较密度不同的亚类以及比较两个受试者时，发现了相当大的差异。对 apoA-1 的翻译后修饰模式的详细分析显示了相当大的蛋白酶活性的证据，特别是在更密集的部分中。