Henan Key Laboratory Cultivation Base of Nanobiological Analytical Chemistry, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, PR China.
Int J Biol Macromol. 2012 Jul-Aug;51(1-2):97-104. doi: 10.1016/j.ijbiomac.2012.04.021. Epub 2012 Apr 26.
In the present study, the formation of one molten globule-like unfolding intermediate of bovine serum albumin (BSA) at pH 11.2 has been established with the help of circular dichroism (CD) spectra, fluorescence spectroscopy and 'phase diagram' approach. Additionally, we have shown the conformational changes occurring in the pH 11.2 intermediate of BSA when it was exposed to different molecular weight polyethylene glycols (PEGs) at varying concentrations. When the pH 11.2 intermediate of BSA was treated by PEG 400 there was induction of secondary and non-native tertiary contacts. In case of PEG 8000 and PEG 20,000, the loss in secondary as well as tertiary structure was observed. PEG 8000 and 20,000 altered the conformation of the pH 11.2 intermediate and resulted in its transition to another intermediate state in which the hydrophobic patches were inaccessible.
在本研究中，借助圆二色性（CD）光谱、荧光光谱和“相图”方法，确定了在 pH 值为 11.2 时牛血清白蛋白（BSA）形成一种类似展开的无定形中间物。此外，我们还展示了当 BSA 在 pH 值为 11.2 的中间物暴露于不同浓度的不同分子量聚乙二醇（PEG）时发生的构象变化。当用 PEG 400 处理 BSA 的 pH 值为 11.2 的中间物时，诱导了二级和非天然三级接触。对于 PEG 8000 和 PEG 20,000，观察到二级和三级结构的丧失。PEG 8000 和 20,000 改变了 pH 值为 11.2 的中间物的构象，并导致其过渡到另一种中间状态，其中疏水性斑点无法接近。
