Fluorescence spectroscopy evaluation of fibrinogen-β-estradiol binding
Fluorescence spectroscopy evaluation of fibrinogen-β-estradiol binding
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DOI：
10.1016/j.jphotobiol.2006.09.001
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发表时间：
2007-02-01
影响因子：
5.4
通讯作者：
Saldanha, Carlota
中科院分区：
文献类型：
--
作者：
Goncalves, Sonia;Santos, Nuno C.;Saldanha, Carlota
进行荧光光谱实验以研究在不同配体浓度下β-雌二醇与纤维蛋白原结合引起的构象变化。纤维蛋白原-β-雌二醇结合的结合常数（K-a）为6.47 × 10（6）M-1，表明高亲和力相互作用。荧光猝灭实验表明，蛋白质四级结构中约30%的色氨酸残基可被离子猝灭剂所接近。在β-雌二醇存在和不存在的情况下，铯离子的淬灭程度最大，碘化物的淬灭程度最小，表明色氨酸残基附近存在带负电荷的残基。在不同的β-雌二醇浓度下获得的淬灭参数显示确认构象变化的改变，可能是由于纤维蛋白原-β-雌二醇结合过程中色氨酸残基的离散重组。这种结合可能是β-雌二醇对降低红细胞聚集和降低心血管风险的作用的原因。(c)2006 Elsevier B. V.保留所有权利。
Fluorescence spectroscopy experiments were performed in order to study conformational changes induced by the binding of beta-estradiol to fibrinogen at different ligand concentrations. The association constant (K-a) obtained for the fibrinogen-beta-estradiol binding was 6.47 x 10(6) M-1, indicating a high affinity interaction. Fluorescence quenching experiments showed that approximately 30% of the tryptophan residues in the protein quaternary structure are accessible to ionic quenchers. The extent of quenching in the absence and presence of beta-estradiol was maximum for cesium ions and minimum for iodide, suggesting the presence of negatively charged residues in the vicinity of the tryptophan residues. The quenching parameters obtained at different beta-estradiol concentrations show alterations that confirm a conformational change, possibly due to a discrete reorganization of tryptophan residues during fibrinogen-beta-estradiol binding. This binding may be responsible for the effects of beta-estradiol on the decrease of erythrocyte aggregation and on cardiovascular risk reduction. (c) 2006 Elsevier B.V. All rights reserved.