de Sousa Rita de Cássia Superbi, Coimbra Jane Sélia dos Reis, da Silva Luis Henrique Mendes, da Silva Maria do Carmo Hespanhol, Rojas Edwin Elard Garcia, Vicente Antonio António Augusto
Separation Process Laboratory, Department of Food Technology, Federal University of Viçosa, P.H. Rolfs Av., s/n, 36570-000 Viçosa, MG, Brazil.
J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Aug 15;877(24):2579-84. doi: 10.1016/j.jchromb.2009.07.002. Epub 2009 Jul 7.
The objective of this study was to determine the thermodynamic parameters (Delta(tr)G, Delta(tr)H and Delta(tr)S) associated with lysozyme and conalbumin partitioning in aqueous two-phases systems (ATPS). Influence of salt type and polyethylene glycol (PEG) concentrations on the partition coefficient of lysozyme and conalbumin from egg white was studied. The evaluated ATPS were composed of PEG 1500 and inorganic salts (sodium citrate and sodium sulfate) at a temperature of 25 degrees C and pH 7.0, with PEG 1500 g mol(-1) concentrations of 14%, 16% and 18% (mass basis). Partitioning of lysozyme in PEG-citrate ATPS was enthalpically driven, however the PEG-sulfate ATPS was entropically driven. The tested systems can be employed for the separation of these two proteins in egg white, due to the fact that lysozyme migrates toward the polymeric phase and conalbumin to the saline phase in both ATPS. A high recovery of conalbumin in the saline phase of the PEG-sulfate ATPS was determined to be enthalpically driven.
本研究的目的是确定与溶菌酶和伴清蛋白在双水相体系（ATPS）中分配相关的热力学参数（Δ(tr)G、Δ(tr)H和Δ(tr)S）。研究了盐类型和聚乙二醇（PEG）浓度对蛋清中溶菌酶和伴清蛋白分配系数的影响。所评估的双水相体系由PEG 1500和无机盐（柠檬酸钠和硫酸钠）组成，温度为25℃，pH值为7.0，PEG 1500的浓度（质量基准）分别为14%、16%和18%。溶菌酶在PEG-柠檬酸盐双水相体系中的分配由焓驱动，而PEG-硫酸盐双水相体系则由熵驱动。由于在这两种双水相体系中溶菌酶都向聚合物相迁移，伴清蛋白向盐水相迁移，因此所测试的体系可用于分离蛋清中的这两种蛋白质。确定伴清蛋白在PEG-硫酸盐双水相体系盐水相中的高回收率是由焓驱动的。
