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标题：Fatty acid binding proteins stabilize leukotriene A4 competition with arachidonic acid but not other lipoxygenase products
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作者：Jennifer S. Dickinson Zimmer ; Douglas F. Dyckes ; David A. Bernlohr 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：2004
卷号：45
期号：11
页码：2138-2144
DOI：10.1194/jlr.M400240-JLR200
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Leukotriene A₄ (LTA₄) is a chemically reactive conjugated triene epoxide product derived from 5-lipoxygenase oxygenation of arachidonic acid. At physiological pH, this reactive compound has a half-life of less than 3 s at 37°C and ∼40 s at 4°C. Regardless of this aqueous instability, LTA₄ is an intermediate in the formation of biologically active leukotrienes, which can be formed through either intracellular or transcellular biosynthesis. Previously, epithelial fatty acid binding protein (E-FABP) present in RBL-1 cells was shown to increase the half-life of LTA₄ to ∼20 min at 4°C. Five FABPs (adipocyte FABP, intestinal FABP, E-FABP, heart/muscle FABP, and liver FABP) have now been examined and also found to increase the half-life of LTA₄ at 4°C to ∼20 min with protein present. Stabilization of LTA₄ was examined when arachidonic acid was present to compete with LTA₄ for the binding site on E-FABP. Arachidonate has an apparent higher affinity for E-FABP than LTA₄ and was able to completely block stabilization of the latter. When E-FABP is not saturated with arachidonate, FABP can still stabilize LTA₄. Several lipoxygenase products, including 5-hydroxyeicosatetraenoic acid, 5,6-dihydroxyeicosatetraenoic acid, and leukotriene B₄, were found to have no effect on the stability of LTA₄ induced by E-FABP even when present at concentrations 3-fold higher than LTA₄.