Moreno F, Cortijo M, González-Jiménez J
Departamento de Química-Física Farmacéutica, Facultad de Farmacia U.C.M., Madrid, Spain.
Photochem Photobiol. 1999 Nov;70(5):695-700.
The binding of the fluorescent probe acrylodan (AC) to human serum albumin (HSA) was studied by fluorescence spectroscopy. The binding isotherms could be fitted to two types of sites. Competition experiments using iodoacetamide suggested that AC binds tightly on HSA by the cysteine-34. Attempts were made to find the location of the second site using high concentrations of warfarin, phenylbutazone, diazepam, indomethacin, palmitic acid or bilirubin in order to displace the bound AC to the HSA. Bilirubin was the only ligand able to displace the bound AC. This result suggests that AC, which is a very hydrophobic molecule also capable of labeling lysine residues, should also bind the human albumin in the primary site of bilirubin, but with less affinity than to the cysteine-34.
采用荧光光谱法研究了荧光探针丙烯基丹（AC）与人血清白蛋白（HSA）的结合。结合等温线可拟合为两种类型的位点。使用碘乙酰胺的竞争实验表明，AC通过半胱氨酸-34紧密结合在HSA上。为了将结合在HSA上的AC置换出来，尝试使用高浓度的华法林、保泰松、地西泮、吲哚美辛、棕榈酸或胆红素来寻找第二个位点的位置。胆红素是唯一能够置换结合的AC的配体。该结果表明，AC是一种疏水性很强且能够标记赖氨酸残基的分子，它也应该在胆红素的主要位点与人白蛋白结合，但亲和力低于与半胱氨酸-34的结合。
