Interaction of Benzbromarone with Subdomains IIIA and IB/IIA on Human Serum Albumin as the Primary and Secondary Binding Regions
Interaction of Benzbromarone with Subdomains IIIA and IB/IIA on Human Serum Albumin as the Primary and Secondary Binding Regions
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DOI：
10.1021/acs.molpharmaceut.0c01004
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发表时间：
2021-01-21
影响因子：
4.9
通讯作者：
Otagiri，Masaki
中科院分区：
文献类型：
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作者：
Yamasaki，Keishi;Kawai，Akito;Otagiri，Masaki
苯溴马隆已被用于治疗痛风超过30年。尽管它显示出与血浆蛋白的高水平结合（>99%），但我们对这种结合的了解还不足以使我们了解其药代动力学和药效学。为了更详细地解决这个问题，我们表征了苯溴马隆与人血清白蛋白（HSA）（血浆中最丰富的蛋白质）的结合。平衡透析和圆二色性的研究结果表明，苯溴马隆强烈结合到一个主要的，以及多个次要网站的HSA和苯溴马隆的溴原子发挥重要作用，在这种高亲和力的结合。X射线晶体学研究表明，苯溴马隆分子结合到亚结构域IB，IIA和IIIA内的疏水口袋。使用位点特异性配体（亚结构域IB;夫西地酸，IIA;华法林，IIIA;地西泮）的抑制实验表明，苯溴马隆结合的主要和次要结合位点分别在亚结构域IIIA和IB/IIA内。最后，脂肪酸对苯溴马隆-HSA相互作用的影响的研究表明，苯溴马隆，当从亚结构域IIIA被油酸钠取代时，可以转移到亚结构域IB或IIA。因此，这些数据将允许对苯溴马隆的置换相互作用进行更相关的评估，特别是在同时给药的药物或也与亚结构域IIIA结合的内源性化合物的情况下。此外，本文中呈现的发现也将可用于设计药物组合疗法，其中需要控制药代动力学和药效学性能。
Benzbromarone has been used for the treatment of gout for more than 30 years. Although it shows a high level of binding to plasma proteins (>99%), our knowledge of this binding is not sufficiently extensive to permit us to understand its pharmacokinetics and pharmacodynamics. To address this issue in more detail, we characterized the binding of benzbromarone to human serum albumin (HSA), the most abundant protein in plasma. Equilibrium dialysis and circular dichroism findings indicated that benzbromarone binds strongly to one primary as well as to multiple secondary sites on HSA and that the bromine atoms of benzbromarone play important roles in this high affinity binding. An X-ray crystallographic study revealed that benzbromarone molecules bind to hydrophobic pockets within subdomains IB, IIA, and IIIA. Inhibition experiments using site specific ligands (subdomain IB; fusidic acid, IIA; warfarin, IIIA; diazepam) indicated that the primary and secondary binding sites that benzbromarone binds to are within subdomains IIIA and IB/IIA, respectively. Lastly, a study of the effect of fatty acids on the benzbromarone–HSA interaction suggested that benzbromarone, when displaced from subdomain IIIA by sodium oleate, could transfer to subdomains IB or IIA. Thus, these data will permit more relevant assessments of the displacement interactions of benzbromarone especially in cases of co-administered drugs or endogenous compounds that also bind to subdomain IIIA. In addition, the findings presented herein will also be useful for designing drug combination therapy in which pharmacokinetic and pharmacodynamic performance need to be controlled.