COMPOSITION OF HIGH DENSITY LIPOPROTEIN SUBCLASSES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。我们对脂蛋白代谢，特别是高密度脂蛋白（HDL）的研究提供了对脂质代谢和转运的独特见解，这将在分子水平上理解动脉粥样硬化。我们实验室开发的方法使我们能够记录以前未报道的HDL分子亚种，每种亚种都可能发挥与HDL相关的特定抗动脉粥样硬化作用。从正常和血脂异常受试者血浆中纯化的HDL亚种显示多种蛋白质。迄今为止，我们已经确定了53种与离散HDL颗粒相关的候选蛋白质。其中，我们还发现了一个新的蛋白质，命名为pol -1，它与两个离散的HDL物种有关。虽然一些HDL亚种的蛋白质组成已经通过western blotting鉴定，但我们寻求通过质谱法获得明确的表征，特别是在我们的抗体产生可疑身份的情况下。这通常是由于抗体特异性和识别能力差。质谱鉴定对于鉴定没有特异性抗体的蛋白质、低浓度蛋白质以及通常认为与HDL无关的蛋白质最为有利。我们对由脂质转移因子如胆固醇转移蛋白、卵磷脂、胆固醇转移酶、磷脂转移蛋白、肝脂肪酶、血浆蛋白酶抑制剂、apoE、apoAIV和载脂蛋白等组成的HDL蛋白组分的了解，对于我们理解HDL介导的冠状动脉疾病保护的代谢功能至关重要。我们现在已经开始研究视网膜色素上皮细胞中脂质转运的作用，因为它们是人类黄斑变性的关键因素，黄斑变性是50岁以上人群失明的主要原因。这包括使用质谱法鉴定视网膜细胞表达的蛋白质。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our studies of lipoprotein metabolism, in particular, the high density lipoproteins (HDL) offer unique insights intolipid metabolism and transport that will be of value in understanding atherosclerosis at a molecular level. Methods developed in our laboratory have allowed us to document previously unreported molecular subspecies of HDL, each of which may play a specific antiatherogenic role associated with HDL. HDL subspecies purified from plasmas of normo- and dyslipidemic subjects reveal a variety of proteins. To date we have identified fifty-three candidate proteins that associate with discrete HDL particles. Among these , we have also discovered a new protein, designated apoL-1, that is associated with two discrete HDL species. While protein compositions of some HDL subspecies have been identified by western blotting, we seek to obtain unequivocal characterization by mass spectroscopy especially in cases were our antibodies produce questionable identities. This frequently results from poor antibody specificity and recognition. Mass spectroscopic identification are of most benefit for the identification of proteins for which we have no specific antibodies, for proteins of low concentration, and for proteins which are not generally considered to associate with HDL. Our understanding of the HDL protein components consisting of lipid transfer factors such as cholesterol transfer protein, lecithin:cholesterol transferase, phosholipid transfer protein, hepatic lipase, plasma protease inhibitors, apoE, apoAIV, and apoL is paramount to our ability to understand the metabolic function of HDL-mediated protection in coronary artery disease. We have now begun to study the role of lipid transport in the retinal pigment epithelial cells, because they are key elements in human macular degeneration, the major cause of blindness in individuals over fifty years of age. This involves the identification of proteins expressed by the retinal cells, using mass spectrometry..