State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China.
J Pharm Biomed Anal. 2010 Jun 5;52(2):280-8. doi: 10.1016/j.jpba.2010.01.006. Epub 2010 Jan 15.
To investigate the interaction between Ractopamine (RAC), an animal growth promoter, and bovine serum albumin (BSA), three spectroscopic approaches (fluorescence, UV-vis and FT-IR) and three different experiments (two mole-ratio and a Job's methods) were used to monitor the biological kinetic interaction procedure. The Stern-Volmer quenching constants K(SV), the binding constants K(a), and the number of binding sites n at 298, 301 and 304 K were evaluated by molecular spectroscopic approaches. The values of enthalpy (-13.47 kJ mol(-1)) and entropy (78.39 J mol(-1)K(-1)) in the reaction indicated that RAC bound to BSA mainly by electrostatic and hydrophobic interaction. The site markers competitive experiments indicated that the binding of RAC to BSA primarily took place in site I. The spectra data matrix was further investigated with multivariate curve resolution-alternating least squares (MCR-ALS), and the concentration profiles and the pure spectra for three species (BSA, RAC and RAC-BSA) existed in the kinetic interaction procedure, as well as the apparent equilibrium constants, were obtained.
为了研究莱克多巴胺（RAC）这种动物生长促进剂与牛血清白蛋白（BSA）之间的相互作用，我们采用三种光谱方法（荧光、紫外-可见分光光度法和傅里叶变换红外光谱法）和三种不同的实验方法（两种摩尔比法和 Job 法）来监测生物动力学相互作用过程。通过分子光谱方法评估了 Stern-Volmer 猝灭常数 K(SV)、结合常数 K(a)和 298、301 和 304 K 时的结合位点数 n。反应的焓值（-13.47 kJ mol(-1))和熵值（78.39 J mol(-1)K(-1))表明，RAC 与 BSA 主要通过静电和疏水相互作用结合。位点标记物竞争实验表明，RAC 与 BSA 的结合主要发生在 I 位点。进一步采用多元曲线分辨-交替最小二乘法（MCR-ALS）对光谱数据矩阵进行分析，获得了动力学相互作用过程中三种物质（BSA、RAC 和 RAC-BSA）的浓度分布和纯光谱，以及表观平衡常数。
