Binding of anandamide to bovine serum albumin
Binding of anandamide to bovine serum albumin
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DOI：
10.1194/jlr.m300170-jlr200
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发表时间：
2003-09-01
影响因子：
6.5
通讯作者：
Hansen, HS
中科院分区：
文献类型：
--
作者：
Bojesen, IN;Hansen, HS
内源性大麻酰胺是类脂的，因此可以与血管系统中的白蛋白结合，就像脂肪酸一样。对于研究其从结合蛋白到细胞膜的转移是至关重要的，因为单体的水相穿梭介导了这种转移。我们已经使用了我们的方法，基于使用白蛋白填充的红细胞幽灵作为分散的生物“参考结合剂”来测量阿南达胺的水相浓度。这些浓度是在缓冲液(pH 7.3)中以低于1的低摩尔比在重新密封的人红细胞膜内与牛血清白蛋白结合的情况下测量的。在0℃、10℃、23℃和37℃下获得数据。平衡离解常数(K-d)随温度的升高而增加，从0℃的6.87+/-0.53 nm增加到37℃的54.92+/-1.91 nm。数据的回归分析表明，在所有四种温度下，牛血清白蛋白都有一个与花青胺高亲和力的结合部位。计算结果表明，苯乙酰胺结合自由能(DeltaG(0))为-43.05kJ·mol(-1)，较大的焓贡献(DeltaH(0))为-42.09kJ·mol(-1)。阿南达胺具有血管扩张活性，与白蛋白的结合可能介导其在房水隔室中的转运。
The endocannabinoid anandamide is of lipid nature and may thus bind to albumin in the vascular system, as do fatty acids. The knowledge of the free water-phase concentration of anandamide is essential for the investigations of its transfer from the binding protein to cellular membranes, because a water-phase shuttle of monomers mediates such transfers. We have used our method based upon the use of albumin-filled red cell ghosts as a dispersed biological "reference binder" to measure the water-phase concentrations of anandamide. These concentrations were measured in buffer (pH 7.3) in equilibrium with anandamide bound to BSA inside resealed human red cell membranes at low molar ratios below one. Data were obtained at 0degreesC, 10degreesC, 23degreesC, and 37degreesC. The equilibrium dissociation constant (K-d) increases with temperature from 6.87 +/- 0.53 nM at 0degreesC to 54.92 +/- 1.91 nM at 37degreesC. Regression analyses of the data suggest that BSA has one high-affinity binding site for anandamide at all four temperatures. The free energy of anandamide binding (DeltaG(0)) is calculated to - 43.05 kJ mol(-1) with a large enthalpy (DeltaH(0)) contribution of -42.09 kJ mol(-1). Anandamide has vasodilator activity, and the binding to albumin may mediate its transport in aqueous compartments.