Department of Chemical Sciences, Indian Institute of Science Education and Research Bhopal, ITI Campus (Gas Rahat) Building, Govindpura, Bhopal 462 023, Madhya Pradesh, India.
J Phys Chem B. 2010 Dec 9;114(48):15839-45. doi: 10.1021/jp106703h. Epub 2010 Nov 15.
The effect of the anionic surfactant sodium dodecyl sulfate (SDS) on the protein human serum albumin (HSA) was studied using steady-state spectroscopy, time-resolved measurements, and circular dichroism spectroscopy. The binding of SDS to the domain IIA of HSA, housing the single tryptophan amino acid residue (Trp214), was monitored, and it was found that this addition of the surfactant takes place in a sequential manner depending upon the concentration of the added surfactant. Both fluorescence intensity and lifetimes of HSA decreased with the increasing concentration of SDS, and the surfactant molecules serve the role of a quencher for the fluorescence of Trp214. Circular dichroism data also support the structural changes induced by SDS. The 17 disulfide bridges present in HSA provide the necessary structural rigidity to the protein. Stern-Volmer plots and thermodynamic parameters have been used to characterize the sequential binding of SDS to HSA, and these parameters not only confirm that the binding is spontaneous in nature but also is quite strong, depending on the concentration of the added surfactant.
利用稳态光谱、时间分辨测量和圆二色性光谱研究了阴离子表面活性剂十二烷基硫酸钠（SDS）对人血清白蛋白（HSA）的影响。监测了 SDS 与 HSA 的域 IIA 的结合，该域包含单个色氨酸氨基酸残基（Trp214），发现这种表面活性剂的添加是依序进行的，取决于添加的表面活性剂的浓度。随着 SDS 浓度的增加，HSA 的荧光强度和寿命均降低，表面活性剂分子充当 Trp214 荧光的猝灭剂。圆二色性数据也支持 SDS 诱导的结构变化。HSA 中存在的 17 个二硫键为蛋白质提供了必要的结构刚性。Stern-Volmer 图和热力学参数已用于表征 SDS 与人血清白蛋白的顺序结合，这些参数不仅证实结合本质上是自发的，而且还相当强，取决于添加的表面活性剂的浓度。
