Department of Chemistry, College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, Hubei, People's Republic of China.
Mol Biol Rep. 2011 Apr;38(4):2445-53. doi: 10.1007/s11033-010-0380-z. Epub 2010 Nov 19.
The interaction between benzophenone (BP) and bovine serum albumin (BSA) was investigated by the methods of fluorescence spectroscopy combined with UV-Vis absorption and circular dichroism (CD) measurements under simulative physiological conditions. The experiment results showed that the fluorescence quenching of BSA by BP was resulted from the formation of a BP-BSA complex and the corresponding association constants (Ka) between BP and BSA at four different temperatures had been determined using the modified Stern-Volmer equation. The enthalpy change (ΔH) and entropy change (ΔS) were calculated to be -43.73 kJ mol(-1) and -53.05 J mol(-1) K(-1), respectively, which suggested that hydrogen bond and van der Waals force played major roles in stabilizing the BP-BSA complex. Site marker competitive experiments indicated that the binding of BP to BSA primarily took place in site I (sub-domain IIA). The conformational investigation showed that the presence of BP decreased the α-helical content of BSA and induced the slight unfolding of the polypeptides of protein, which confirmed some micro-environmental and conformational changes of BSA molecules.
在模拟生理条件下，采用荧光光谱法结合紫外-可见吸收法和圆二色性（CD）测量法研究了二苯甲酮（BP）与牛血清白蛋白（BSA）之间的相互作用。实验结果表明，BP 对 BSA 的荧光猝灭是由于形成了 BP-BSA 复合物，并且使用改进的 Stern-Volmer 方程确定了在四个不同温度下 BP 与 BSA 之间的相应结合常数（Ka）。计算得到焓变（ΔH）和熵变（ΔS）分别为-43.73 kJ mol(-1)和-53.05 J mol(-1) K(-1)，这表明氢键和范德华力在稳定 BP-BSA 复合物中起主要作用。位点标记竞争实验表明，BP 与 BSA 的结合主要发生在 I 位点（亚结构域 IIA）。构象研究表明，BP 的存在降低了 BSA 的α-螺旋含量，并诱导蛋白质多肽的轻微展开，这证实了 BSA 分子的一些微环境和构象变化。
