THE 94-KDA TO 97-KDA MOUSE MACROPHAGE MEMBRANE-PROTEIN THAT RECOGNIZES OXIDIZED LOW-DENSITY-LIPOPROTEIN AND PHOSPHATIDYLSERINE-RICH LIPOSOMES IS IDENTICAL TO MACROSIALIN, THE MOUSE HOMOLOG OF HUMAN CD68
THE 94-KDA TO 97-KDA MOUSE MACROPHAGE MEMBRANE-PROTEIN THAT RECOGNIZES OXIDIZED LOW-DENSITY-LIPOPROTEIN AND PHOSPHATIDYLSERINE-RICH LIPOSOMES IS IDENTICAL TO MACROSIALIN, THE MOUSE HOMOLOG OF HUMAN CD68
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DOI：
10.1073/pnas.92.21.9580
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发表时间：
1995-10-10
影响因子：
11.1
通讯作者：
STEINBERG, D
中科院分区：
文献类型：
--
作者：
RAMPRASAD, MP;FISCHER, W;STEINBERG, D
我们以前曾报道过从小鼠腹腔巨噬细胞中部分纯化94- 97-kDa质膜蛋白，该蛋白结合氧化修饰的低密度脂蛋白（OxLDL）和富含磷脂酰丝氨酸的脂质体，我们现在已经确定该蛋白为macrosialin，这是一种以前克隆的巨噬细胞限制性膜蛋白，属于溶酶体相关膜蛋白家族（人CD 68的小鼠同源物）。在94-至97-kDa蛋白质的纯化过程的早期，在190-200 kDa处出现新的OxLDL-结合带，并与94-至97-kDa蛋白质共纯化。来自该更高分子量配体-结合带的胰蛋白酶肽的HPLC模式与来自93-至97-kDa带的胰蛋白酶肽的HPLC模式紧密匹配。（9、9和15个残基）存在于纯化的94-至97-kDa条带和190-至200-kDa条带中，并且针对大唾液酸蛋白中的肽序列产生的抗血清识别这两个条带。针对大唾液酸蛋白的抗血清沉淀大部分94-至97-kDa OxLDL结合物质，我们的结论是，OxLDL与小鼠巨噬细胞膜的结合部分归因于巨唾液酸蛋白。我们以前的研究表明，OxLDL与氧化红细胞和凋亡胸腺细胞竞争结合小鼠腹腔巨噬细胞，巨唾液酸蛋白是否在完整巨噬细胞识别氧化低密度脂蛋白和氧化损伤细胞中起作用仍不确定。
We have previously reported the partial purification of a 94- to 97-kDa plasma membrane protein from mouse peritoneal macrophages that binds oxidatively modified low density lipoprotein (OxLDL) and phosphatidylserine-rich liposomes, We have now identified that protein as macrosialin, a previously cloned macrophage-restricted membrane protein in the lysosomal-associated membrane protein family (mouse homologue of human CD68). Early in the course of purification of the 94- to 97-kDa protein, a new OxLDL-binding band at 190-200 kDa appeared and copurified with the 94- to 97-kDa protein, The HPLC pattern of tryptic peptides from this higher molecular mass Ligand-binding band closely matched that derived from the 93- to 97-kDa band, Specifically, the same three macrosialin-derived tryptic peptides (9, 9, and 15 residues) were present in the purified 94- to 97-kDa band and in the 190- to 200-kDa band and antisera raised against peptide sequences in macrosialin recognized both bands, An antiserum against macrosialin precipitated most of the 94- to 97-kDa OxLDL-binding material, We conclude that the binding of OxLDL to mouse macrophage membranes is in part attributable to macrosialin, Our previous studies show that OxLDL competes with oxidized red blood cells and with apoptotic thymocytes for binding to mouse peritoneal macrophages, Whether macrosialin plays a role in recognition of OxLDL and oxidatively damaged cells by intact macrophages remains uncertain.