Effect of physiological concentration of urea on the conformation of human serum albumin
Effect of physiological concentration of urea on the conformation of human serum albumin
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DOI：
10.1093/jb/mvm027
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发表时间：
2007-02-01
影响因子：
2.7
通讯作者：
Khan, Rizwan Hasan
中科院分区：
文献类型：
--
作者：
Gull, Nuzhat;Sen, Priyankar;Khan, Rizwan Hasan
我们报道了非常低浓度（< 0.1 M）的尿素（一种广泛使用的化学变性剂）在pH为7时诱导水溶性球状蛋白人血清白蛋白（HSA）的结构形成。我们提出的结果表明，在10毫米尿素(U)和20毫米单甲基脲（MMU）的存在下，α -螺旋分别增加了近8%和5%。远紫外和近紫外圆二色性研究以及色氨酸荧光和1-苯胺-8-萘磺酸（ANS）结合支持我们的观点。我们假设，在如此低的浓度下，U和MMU都改变了溶剂结构，增加了介电常数，从而增加了疏水性，从而增强了α -螺旋含量。低尿素方案的这些结果意义重大，因为生理血尿素在2.5至7.5 mM之间。
We report that the presence of very low concentrations (< 0.1 M) of urea, a widely used chemical denaturant, induces structure formation in the water-soluble globular protein human serum albumin (HSA) at pH 7. We have presented results suggesting an almost 8% and 5% increase in alpha-helix in the presence of 10 mM urea (U) and 20 mM monomethylurea (MMU), respectively. Far and near-UV circular dichroism studies along with tryptophan fluorescence and 1-anilino-8-naphthalenesulphonicacid (ANS) binding support our view. We hypothesize that both U and MMU, at such low concentrations, modify the solvent structure, increase the dielectric constant and consequently increase hydrophobic forces resulting in enhanced alpha-helical content. The implications of these results of the lower urea regime are significant because the physiological blood urea ranges from 2.5 to 7.5 mM.