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标题：Vesicle-binding properties of wild-type and cysteine mutant forms of α1 domain of apolipoprotein B
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作者：Jeanine A. DeLozier ; John S. Parks ; Gregory S. Shelness 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2001
卷号：42
期号：3
页码：399-406
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Previous studies demonstrated that structural perturbation of the α₁ domain of apolipoprotein B (apoB) blocked the initiation of lipoprotein assembly. We explored the hypothesis that this domain may interact with the inner leaflet of the endoplasmic reticulum membrane in a manner that may nucleate microsomal triglyceride transfer protein-dependent lipid sequestration. ApoB-17 (amino-terminal 17% of apoB), which contains most of the α₁ domain, was expressed stably in rat hepatoma cells and recovered from medium in lipid-poor form. On incubation with phospholipid vesicles composed of 1-myristol-2-myristoyl- sn -glycero-3-phosphocholine or 1-palmitoyl-2-oleoyl- sn -gylycero-3-phosphocholine, apoB-17 underwent vesicle binding and was recovered in the d 1 domain of apoB are stabilized by intramolecular disulfide bonds. In contrast to apoB-17 chemically reduced in vitro, forms of apoB-17 bearing pairwise cysteine-to-serine substitutions were recovered in soluble form from transiently transfected COS-1 cell extracts. Although individual disruption of disulfide bond 2 or 4 in apoB-28 and apoB-50 was previously shown to block lipoprotein assembly in vivo, these alterations had no impact on the ability of apoB-17 to bind to phospholipid vesicles in vitro or on its capacity to form recombinant lipoprotein particles. These results suggest that while the vesicle/lipid-binding property of the α₁ domain may reflect an essential role required for the initiation of lipoprotein formation, some other aspect of α₁ domain function is perturbed by disruption of native disulfide bonds. —DeLozier, J. A., J. S. Parks, and G. S. Shelness. Vesicle-binding properties of wild-type and cysteine mutant forms of α₁ domain of apolipoprotein B. J. Lipid Res. 2001. 42: 399–406.
关键词：lipoprotein assembly ; recombinant lipoproteins ; disulfide bonds ; apoB-17 ; vesicle-binding assay