Apolipoprotein L, a new human high density lipoprotein apolipoprotein expressed by the pancreas - Identification, cloning, characterization, and plasma distribution of apolipoprotein L
Apolipoprotein L, a new human high density lipoprotein apolipoprotein expressed by the pancreas - Identification, cloning, characterization, and plasma distribution of apolipoprotein L
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DOI：
10.1074/jbc.272.41.25576
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发表时间：
1997-10-10
影响因子：
4.8
通讯作者：
Kane, JP
中科院分区：
文献类型：
--
作者：
Duchateau, PN;Pullinger, CR;Kane, JP
在本研究中，我们鉴定了人高密度脂蛋白中存在的一种新的蛋白质，我们将其命名为载脂蛋白L。采用高效液相等电泳法和高分辨双向凝胶电泳法，从免疫分离的高密度脂蛋白(Lp(A-I))中鉴定出载脂蛋白L，并对其进行了部分测序。该蛋白仅在胰腺中表达，经逆转录-聚合酶链式反应克隆出编码全长蛋白的c DNA序列，推导的氨基酸序列包含383个氨基酸残基，其中包括一个典型的12个氨基酸的信号肽，与已知序列没有明显的同源性，该蛋白是一个表观分子质量为42 kDa的单链多肽，针对该蛋白的抗体检测到一个截短的形式，分子质量为39 kDa，这两种形式主要与免疫亲和力分离的含apoA-I的脂蛋白有关，主要检测到密度范围为1.123<；d<；1.21g/ml，血浆中未检测到游离APOL。用抗载脂蛋白免疫亲和层析直接从血浆中纯化含载脂蛋白的脂蛋白(L)。L的LP非变性凝胶电泳图显示两个主要分子物种，表观直径分别为12.2~17和10.4~12.2 nm。此外，Lp(L)既表现出前β电迁移率，又表现出α电迁移率。在含APOL的脂蛋白颗粒中也检测到载脂蛋白A-I、A-II、A-IV和C-III。
In this study, we have identified and characterized a new protein present in human high density lipoprotein that we have designated apolipoprotein L. Using a combination of liquid-phase isoelectrophoresis and high resolution two-dimensional gel electrophoresis, apolipoprotein L was identified and partially sequenced from immunoisolated high density lipoprotein (Lp(A-I)). Expression was only detected in the pancreas, The cDNA sequence encoding the full-length protein was cloned using reverse transcription-polymerase chain reaction, The deduced amino acid sequence contains 383 residues, including a typical signal peptide of 12 amino acids, No significant homology was found with known sequences, The plasma protein is a single chain polypeptide with an apparent molecular mass of 42 kDa, Antibodies raised against this protein detected a truncated form with a molecular mass of 39 kDa, Both forms were predominantly associated with immunoaffinity-isolated apoA-I-containing lipoproteins and detected mainly in the density range 1.123 < d < 1.21 g/ml. Free apoL was not detected in plasma. Anti-apoL immunoaffinity chromatography was used to purify apoL-containing lipoproteins (Lp(L)) directly from plasma. Nondenaturing gel electrophoresis of Lp(L) showed two major molecular species with apparent diameters of 12.2-17 and 10.4-12.2 nm. Moreover, Lp(L) exhibited both pre-beta and alpha electromobility. Apolipoproteins A-I, A-II, A-IV, and C-III were also detected in the apoL-containing lipoprotein particles.