β-乳球蛋白-IgG混合物的反胶束萃取平衡及其机理探讨

Studies on the mechanism and extraction equilibrium of β-lactoglobulin and immunoglobulin G from their mixtures into reversed micelles

依据堆砌几何模型,选择琥珀酸二(2-乙基己基)酯磺酸钠(AOT)-异辛烷反胶束萃取体系,研究了β-乳球蛋白单一蛋白体系中以及β-乳球蛋白与免疫球蛋白G(1︰1)混合物体系中蛋白质的分布特性,并探讨了AOT-异辛烷反胶束体系分离分级乳蛋白的机理。β-乳球蛋白在单一蛋白或混合蛋白(Wβ-Lg︰WIgG为1︰1)体系中的反胶束萃取率均随着水相pH值增加(pH值为5.0￣9.0)而降低,随水相[Na+]浓度升高(0.06￣0.35mol/L)而逐渐增加,随水相起始蛋白质量浓度增加(0.75￣3.0g/L)而降低,但免疫球蛋白G可明显促进β-乳球蛋白在反胶束有机相中的增溶。在混合蛋白质体系中,β-乳球蛋白与免疫球蛋白G可分别趋于富集在有机相和水相,显示出AOT-异辛烷反胶束体系在牛初乳乳清蛋白分离方面具有应用潜力。

Based on a simplified geometrical packing model, a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)-in-isooctane reversed micellar system was set up to investigate the separation behaviors of β-lactoglobulin in a pure solution or an aqueous 1︰1 mixed solution of β-lactoglobulin and immunoglobulin G (IgG) in this paper. The separation behaviors of IgG and separation mechanism of proteins in the reversed micellar system were also discussed. The resulting extraction of β-lactoglobulin increased with an increasing sodium concentration (0.06~0.35 mol/L) and decreased with an increasing pH (pH=5.0~9.0) and initial concentration of proteins(0.75~3.0 g/L)in the aqueous in a pure or mixed proteins system. β-lactoglobulin and IgG could distribute to an organic or aqueous phase differently and IgG could promote the distribution of β-lactoglobulin to the organic phase in the mixed proteins system. It showed an application potential of reversed micellar system in proteins separation of colostrums.