PLASMA-MEMBRANE FATTY-ACID-BINDING PROTEIN (FABP(PM)) OF THE SHEEP PLACENTA
PLASMA-MEMBRANE FATTY-ACID-BINDING PROTEIN (FABP(PM)) OF THE SHEEP PLACENTA
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DOI：
10.1016/0005-2760(94)90043-4
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发表时间：
1994-09-15
期刊：
影响因子：
--
通讯作者：
DUTTAROY, AK
中科院分区：
文献类型：
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作者：
CAMPBELL, FM;GORDON, MJ;DUTTAROY, AK
脂肪酸结合蛋白（FABP（pm））已被确定和羊胎盘膜的特点。[C-14]油酸酯与胎盘膜的结合具有时间和温度依赖性。添加20倍过量的未标记的油酸、棕榈酸或亚油酸将[C-14]油酸酯与膜的结合减少至总结合的约50%，而类似浓度的D-α-生育酚不影响[C-14]油酸酯结合。这表明结合位点对脂肪酸是特异性的。[C-14]油酸酯的特异性结合通过膜的热变性或胰蛋白酶消化而减少，这表明脂肪酸结合位点是蛋白质性质的。然后从绵羊胎盘膜中溶解FABP（pm），随后使用油酸-琼脂糖亲和柱纯化至电泳均一。经SDS-PAGE和凝胶渗透色谱法测定，纯化的FABP（pm）的表观分子量为40 kDa。纯化蛋白的[C-14]油酸酯结合活性也通过PAGE随后的放射自印迹来证实。油酸的特异性结合为每毫克膜蛋白约1.5纳摩尔。我们的数据表明羊胎盘膜中存在FABP（pm）。
Fatty acid-binding protein (FABP(pm)) has been identified and characterised from sheep placental membranes. Binding of [C-14]oleate to placental membranes was found to be time- and temperature-dependent. Addition of a 20-fold excess unlabelled oleic, palmitic, or linoleic acid reduced the binding of [C-14]oleate to the membranes to around 50% of total binding, whereas D-alpha-tocopherol at similar concentrations did not affect [C-14]oleate binding. This indicates that the binding sites are specific to fatty acids. Specific binding of [C-14]oleate was reduced by heat denaturation or trypsin digestion of the membranes, suggesting that the fatty acid-binding sites are protein in nature. FABP(pm) was then solubilised from sheep placental membranes, and subsequently purified to electrophoretic homogeneity using an oleate-agarose affinity column. The purified FABP(pm) had an apparent molecular mass of 40 kDa, as determined by SDS-PAGE and by gel permeation chromatography. The [C-14]oleate-binding activity of the purified protein was also confirmed by PAGE followed by autoradioblotting. The specific binding for oleate was around 1.5 nmol per mg of membrane protein. Our data indicate the presence of FABP(pm) in sheep placental membranes.