碲钨酸盐磁性纳米复合材料选择性分离鸡蛋清中卵清蛋白

Preparation of Tungstotellurate (Ⅵ)-coated Magnetic Nanoparticles for Separation and Purification of Ovalbumin in Egg White

将碲钨酸盐(Na6[TeW6O24]·22H20,TeW)通过静电作用负载到支状聚乙烯亚胺(PEI)修饰的磁性纳米粒子(MNP)表面,得到新型的基于多金属氧酸盐的复合材料(TeW@MNP),采用红外光谱、能谱、扫描电镜等对其进行表征。蛋白质吸附研究结果表明,该磁性纳米复合材料对卵清蛋白具有选择性吸附作用。考察了吸附时间、离子强度、洗脱剂种类和用量等对分离纯化效率的影响,在pH4.0时,0.5mgTeW@MNP对200μL100μg/mL卵清蛋白的吸附效率为91.6%,最大理论吸附容量为373.4mg/g,以0.1%SDS为洗脱剂时,对卵清蛋白的洗脱效率为98.1%。SDS-PAGE实验表明,采用此复合材料可成功地从卵清样品中分离出纯度较高的卵清蛋白。本研究以TeW@MNP复合物为固相萃取剂,建立了从鸡蛋清中分离纯化卵清蛋白的方法,拓宽了多金属氧酸盐的应用范围。

TungstotellurateⅥ-coated magnetic nanoparticles(MNP) were prepared by immobilization of tungstotellurate Ⅵ salt onto the surface of branched polyethyleneimine(PEI)-modified magnetic nanoparticles via electrostatic interaction. The structure and composition of TeW@MNP were confirmed by characterization with FT-IR, EDS and SEM. The obtained TeW@MNP composite had proven to be a promising adsorbent for the adsorption of ovalbumin in egg whites. Approximately 0.5 mg of TeW@MNP composite gave rise to a maximum adsorption efficiency of 91.6% for 100 μg/mL ovalbumin in 200 μL of sample solution at pH 4.0(BR buffer). The retained ovalbumin was readily recovered by using 0.1% SDS as a stripping reagent, providing a recovery of 98.1%. The adsorption behavior of ovalbumin fitted Langmuir model, corresponding to a theoretical adsorption capacity of 373.4 mg/g. The TeW@MNP composite was practically applied to the selective isolation of ovalbumin from egg whites, and SDS-PAGE assay results clearly indicated that the ovalbumin with high purity was obtained. The above experimental results illustrated the great application potentials of polyoxometalates for protein isolation and purification and extended the application scope of polyoxometalates in life science field.