ATHEROGENICITY OF POSTPRANDIAL TRIGLYCRIDE-RICH LIPOPROTEINS (PPTGRLP)

两个人类单核巨噬细胞(HMM)膜结合蛋白(MBP)200和235是与富含甘油三酯的脂蛋白中的载脂蛋白(Apo)B-48结构域结合的候选受体，不依赖于apoE而摄取。纯化的还原的MBP200r特征胰蛋白酶多肽的微序列分析。一种模拟独特的、明确的10个残基序列的合成肽(AEGLMVTGGR)在一维和二维分析中诱导出特异性识别MBP200、235和200R的抗肽抗体，表明1)配体结合蛋白被测序，2)MBP200和235还原后产生MBP200R。这些抗体在人类血液传播、THP-1、U937 MMS和内皮细胞(EC)中识别MBPS，但在人成纤维细胞或中国仓鼠卵巢(CHO)细胞中不识别MBPS。荧光激活细胞分选(FACS)分析确定MM表面的MBPS是受体功能所必需的。这个10个残基、明确的MBP200衍生序列是唯一的，在现有的蛋白质数据库中没有匹配。抗肽抗体与具有这种受体活性的网状内皮细胞的MBPS结合，但不与缺乏这种受体活性的细胞中的蛋白质结合。这些研究提供了第一个直接的蛋白质序列和免疫化学数据，表明在人类单核细胞、巨噬细胞和内皮细胞中存在一种新的、独特的富含甘油三酯的脂蛋白的载脂蛋白B受体。抗肽抗体揭示了MBP200和MBP235的相互关系：人类单核巨噬细胞上富含甘油三酯的脂蛋白的独特载脂蛋白特异性受体。

Two human monocyte-macrophage (HMM) membrane binding proteins, (MBP) 200 and 235, are receptor candidates that bind to the apolipoprotin (apo)B-48 domain in triglyceride-rich lipoproteins for uptake independent of apoE. Microsequence analysis of the purified reduced MBP 200R characterized tryptic peptides of MBP 200R. A synthetic peptide mimicking a unique, unambiguous 10-residue sequence (AEGLMVTGGR) induced antipeptide anti- bodies that specifically recognized MBP 200, 235 and 200R, in 1- and 2- dimensional analyses, indicating 1) the ligand binding protein was sequenced and 2) MBP 200 and 235 yielded MBP 200R upon reduction. These antibodies identified the MBPs in human blood-borne, THP-1, U937 MMs, and endothelial cells (EC) but not in human fibroblasts or Chinese hamster ovary (CHO) cells. Fluorescence activated cell sorting (FACS) analysis located the MBPs on the MM surface as necessary for receptor function. The 10-residue, unambiguous MBP 200-derived sequence is unique, with no matches in extant protein databases. Antipeptide antibodies bind to the MBPs in reticuloendothelial cells that have this receptor activity, but not to proteins in cells that lack this receptor activity. These studies provide the first direct protein sequence and immunochemical data that a new, unique apoB receptor for triblyceride-rich lipoproteins exists in human monocytes, macrophages, and endothelial cells. Antipeptide antibodies reveal interrelationships of MBP 200 and MBP 235: unique apoB-specific receptors for triglyceride-rich lipoproteins on human monocyte-macrophages.