Cytosolic fatty acid binding proteins catalyze two distinct steps in intracellular transport of their ligands
Cytosolic fatty acid binding proteins catalyze two distinct steps in intracellular transport of their ligands
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DOI：
10.1023/a:1020550405578
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发表时间：
2002-10
影响因子：
4.3
通讯作者：
R. Weisiger
中科院分区：
文献类型：
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作者：
R. Weisiger
细胞质长链脂肪酸结合蛋白 (FABP) 存在于代谢脂肪酸的组织中。与大多数脂质结合蛋白一样，它们的具体功能仍不清楚。已经描述了两个类。膜活性 FABP 在蛋白质结合位点和膜之间交换脂肪酸时直接与膜相互作用，而膜非活性 FABP 仅与水溶液中已有的脂肪酸结合。尽管有这些结合蛋白，细胞质中的大多数脂肪酸似乎与膜结合。本文回顾了表明 FABP 催化脂肪酸在细胞内膜之间转移的数据，通常跨越相当大的细胞内距离。该过程分三个不同的步骤进行：脂肪酸从“供体”膜解离，脂肪酸扩散穿过中间的水层，以及与“受体”膜结合。膜活性 FABP 催化脂肪酸从供体膜解离并与受体膜结合，而膜非活性 FABP 催化脂肪酸在水性细胞质中的扩散。因此，FABP 催化细胞内转运的所有三个步骤。已经开发出一种简单的定量模型，可以预测细胞内转运速率与结合蛋白浓度、亲和力和扩散迁移率的函数关系。不同的 FABP 可能已经进化以匹配它们所在细胞类型的特定运输要求。 (Mol Cell Biochem239: 35–43, 2002)
Cytosolic long-chain fatty acid binding proteins (FABPs) are found in tissues that metabolize fatty acids. Like most lipid binding proteins, their specific functions remain unclear. Two classes have been described. Membrane-active FABPs interact directly with membranes during exchange of fatty acids between the protein binding site and the membrane, while membrane-inactive FABPs bind only to fatty acids that are already in aqueous solution. Despite these binding proteins, most fatty acids in cell cytoplasm appear to be bound to membranes. This paper reviews data suggesting that FABPs catalyze transfer of fatty acids between intracellular membranes, often across considerable intracellular distances. This process occurs in three distinct steps: dissociation of the fatty acid from a ‘donor’ membrane, diffusion of the fatty acid across the intervening water layer, and binding to an ‘acceptor’ membrane. Membrane-active FABPs catalyze dissociation of the fatty acid from the donor membrane and binding to the acceptor membrane, while membrane-inactive FABPs catalyze diffusion of fatty acids across the aqueous cytosol. Thus, FABPs catalyze all three steps in intracellular transport. A simple quantitative model has been developed that predicts the rate of intracellular transport as a function of the concentration, affinity and diffusional mobility of the binding protein. Different FABPs may have evolved to match the specific transport requirements of the cell type within which they are found. (Mol Cell Biochem239: 35–43, 2002)