Lam K T, Borkan S, Claffey K P, Schwartz J H, Chobanian A V, Brecher P
Department of Biochemistry, Boston University School of Medicine, Massachusetts 02118.
J Biol Chem. 1988 Oct 25;263(30):15762-8.
A protein from rat kidney was characterized that had several properties common to a multigene family of fatty acid binding proteins identified in other tissues. The putative kidney fatty acid binding protein (FABP) was purified from the soluble fraction of kidney homogenates using gel filtration and ion exchange chromatography. It was relatively abundant, had an apparent molecular mass of 15.5 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, bound equimolar amounts of oleic acid, and could be distinguished from other FABPs on the basis of size, amino acid composition, and tissue distribution. Polyclonal antibodies to kidney FABP were obtained and used to show that only kidney contained the 15.5-kDa protein, although the antibodies also recognized a slightly larger and less abundant protein in kidney that also was present in bladder. Rat kidney also contained heart FABP, and the properties of both FABPs in rat kidney were compared. The distribution of both proteins within the kidney differed, with kidney FABP being localized almost exclusively within the cortex, whereas heart FABP was found both in cortex and medulla. Kidney FABP was expressed developmentally after the neonatal period, whereas heart FABP was present in both neonatal and adult kidney at comparable amounts. Hypertension induced by mineralocorticoids or infusion of angiotensin II caused a marked suppression of kidney FABP expression, whereas amounts of heart FABP in kidney were unchanged. The studies showed that rat kidney contains at least two FABPs, and that these proteins are differentially regulated, suggesting that functional differences between the proteins may exist.
对一种来自大鼠肾脏的蛋白质进行了表征，它具有与在其他组织中鉴定出的脂肪酸结合蛋白多基因家族的几种共同特性。假定的肾脏脂肪酸结合蛋白（FABP）通过凝胶过滤和离子交换色谱从肾脏匀浆的可溶部分中纯化出来。它相对丰富，通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳估计其表观分子量为15.5 kDa，能结合等摩尔量的油酸，并且可以根据大小、氨基酸组成和组织分布与其他FABP区分开来。获得了针对肾脏FABP的多克隆抗体，并用于显示只有肾脏含有15.5 kDa的蛋白质，尽管这些抗体也识别出肾脏中一种稍大且含量较少的蛋白质，该蛋白质在膀胱中也存在。大鼠肾脏还含有心脏FABP，并比较了大鼠肾脏中两种FABP的特性。两种蛋白质在肾脏内的分布不同，肾脏FABP几乎完全定位于皮质内，而心脏FABP在皮质和髓质中均有发现。肾脏FABP在新生儿期后发育表达，而心脏FABP在新生儿和成年肾脏中的含量相当。盐皮质激素诱导的高血压或输注血管紧张素II导致肾脏FABP表达明显受到抑制，而肾脏中心脏FABP的含量未发生变化。这些研究表明大鼠肾脏至少含有两种FABP，并且这些蛋白质受到不同的调节，这表明这些蛋白质之间可能存在功能差异。
