Hagarová D, Breier A
Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia.
Gen Physiol Biophys. 1995 Aug;14(4):277-91.
Aqueous two-phase systems formed by mixing polyethylene glycol (PEG) and dextran (DXT) were studied. The composition of DXT and PEG phase was established by the size exclusion HPLC method. The concentrations of DXT and PEG in both phases as a function of total concentration of both polymers was fitted by nonlinear regression. This procedure yielded an empirical numerical model (with two independent variables: bulk concentration of DXT and PEG) characterizing the composition of either phase at any applied concentration of the polymers. The distributions of bovine serum albumin (BSA) and immunoglobulin G (IgG) were studied in this system in relation to the composition of both phases. Both proteins were predominantly distributed in the dextran phase. The protein affinity to the respective phase was found to increase with: i) the increasing phase dextran concentration; and ii) the decreasing phase PEG concentration. Chemical modification of primary amino groups of BSA by 2,4,6-trinitrobenzene sulfonic acid (TNBS) raised the affinity of the conjugate to the less polar PEG phase.
研究了通过混合聚乙二醇（PEG）和葡聚糖（DXT）形成的双水相系统。采用尺寸排阻高效液相色谱法确定了DXT相和PEG相的组成。通过非线性回归拟合了两相中DXT和PEG的浓度与两种聚合物总浓度的函数关系。该过程产生了一个经验数值模型（有两个自变量：DXT和PEG的本体浓度），用于表征在任何聚合物应用浓度下任一相的组成。研究了该系统中牛血清白蛋白（BSA）和免疫球蛋白G（IgG）的分布与两相组成的关系。两种蛋白质主要分布在葡聚糖相中。发现蛋白质对各自相的亲和力随着以下因素增加：i）相葡聚糖浓度的增加；ii）相PEG浓度的降低。用2,4,6-三硝基苯磺酸（TNBS）对BSA的伯氨基进行化学修饰提高了共轭物对极性较小的PEG相的亲和力。
