多聚亚基蛋白质在固-液界面团聚的测量与表征

以血红蛋白和乙肝表面抗原(HBsAg)为模型,联用双偏振光干涉分析仪(DPI)和原子力显微镜(AFM)研究在固-液界面上的吸附行为.结果发现:当溶液环境中血红蛋白的质量浓度为1.08 mg/mL时,测得在硅羟基表面吸附的平均厚度为3.54 nm,蛋白颗粒直径达60～ 150 nm,远高于血红蛋白的分子尺寸,说明血红蛋白在固-液界面上发生团聚.当HBsAg质量浓度为0.67 mg/mL时,测得在硅羟基表面及DEAE琼脂糖表面吸附的平均厚度分别为1.06和23.69 nm,表面吸附的蛋白颗粒直径分别为288～401和520 ～ 971 nm,是单分子HBsAg尺寸的13.1～44.1倍,表明在模型蛋白表面都形成了大的团聚体.

Measurement and characterization of agglomeration of multimeric proteins on solid-liquid interface

Using two multimeric proteins,i.e.,hemoglobin and hepatitis B surface antigen（HBsAg）,as model proteins,the adsorption behaviors on solid-liquid interface were analyzed by dual polarization interferometry（DPI） and atomic force microscope.It was shown that the average thickness of hemoglobin attached to unmodified DPI sensor chip was 3.54 nm and the diameters of protein particles were 60 nm to 150 nm at 1.08 mg/mL,and it was far larger than the size of single hemoglobin molecular,thus indicating that hemoglobin was agglomerated on Si—OH surface.Under the concentration of 0.67 mg/mL,the layer thicknesses of adsorbed HBsAg was 1.04 nm and 23.69 nm on unmodified surface and DEAE agarose surface respectively,and the corresponding diameters were 288 nm to 401 nm and 520 nm to 971 nm,it was 13.1-44.1 fold of single HBsAg molecule.The result showed that big agglomerates were formed on both surfaces.