Impaired drug-binding capacities of in vitro and in vivo glycated albumin
Impaired drug-binding capacities of in vitro and in vivo glycated albumin
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DOI：
10.1016/j.biochi.2012.05.017
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发表时间：
2012-09-01
期刊：
影响因子：
3.9
通讯作者：
Rondeau, Philippe
中科院分区：
文献类型：
--
作者：
Baraka-Vidot, Jennifer;Guerin-Dubourg, Alexis;Rondeau, Philippe
白蛋白是血液中的主要循环蛋白，在糖尿病患者中可发生糖基化增加。这种血浆蛋白的主要性质之一是它与包括华法林和酮洛芬在内的许多治疗药物具有很强的亲和力。在这项研究中，我们调查了在体外或体内糖基化是否有任何与糖基化有关的显著变化，以及人血清白蛋白与两种治疗药物的结合。研究了糖化纯化蛋白在体外和体内的氧化还原状态和酮胺含量等结构参数，以及它们对华法林和酮洛芬的亲和力。采用Scatchard法测定游离药物浓度和离解常数。另一种基于荧光光谱的方法也被用来评估药物结合性能。从糖尿病患者中提纯的白蛋白或用葡萄糖或甲基乙醛糖化的白蛋白，在测定其酮胺、游离硫、氨基和羰基含量后，其氧化和糖基化水平被提高。同时，体外和体内糖化白蛋白的结合亲和力显著受损，如较高的解离常数值所表明的，并被较高的游离药物分数所证实。在较小的程度上，这种改变也显著影响糖尿病白蛋白的亲和力，这表明荧光光谱中的静态猝灭较低。这项工作提供了有用的信息，支持体内糖尿病白蛋白可能是监测糖尿病生理病理的最佳糖基化模型，并且对于了解白蛋白糖基化是否有助于糖尿病期间药物反应的可变性是有价值的。(C)2012年爱思唯尔·马森公司。版权所有。
Albumin, the major circulating protein in blood, can undergo increased glycation in diabetes. One of the main properties of this plasma protein is its strong affinity to bind many therapeutic drugs, including warfarin and ketoprofen. In this study, we investigated whether or not there were any significant changes related to in vitro or in vivo glycation in the structural properties and the binding of human albumin to both therapeutic drugs. Structural parameters, including redox state and ketoamine contents of in vitro and in vivo glycated purified albumins, were investigated in parallel with their affinity for warfarin and ketoprofen. High-performance liquid chromatography was used to determine the free drug concentrations and dissociation constants according to the Scatchard method. An alternative method based on fluorescence spectroscopy was also used to assess drug-binding properties. Oxidation and glycation levels were found to be enhanced in albumin purified from diabetic patients or glycated with glucose or methylglyoxal, after determination of their ketoamine, free thiol, amino group and carbonyl contents. In parallel, significant impairments in the binding affinity of in vitro and in vivo glycated albumin, as indicated by the higher dissociation constant values and confirmed by higher free drug fractions, were observed. To a lesser extent, this alteration also significantly affected diabetic albumin affinity, indicated by a lower static quenching in fluorescence spectroscopy. This work provides useful information supporting in vivo diabetic albumin could be the best model of glycation for monitoring diabetic physiopathology and should be valuable to know if glycation of albumin could contribute to variability in drugs response during diabetes. (C) 2012 Elsevier Masson SAS. All rights reserved.