超高压处理对β-伴大豆球蛋白抗原性及结构的影响

Effect of high hydrostatic pressure treatment on antigenicity and structure of soybeanβ-conglycinin

探究超高压处理对β-伴大豆球蛋白抗原性及结构的影响,为大豆蛋白的脱敏提供方法。通过等电点冷沉法提取β-伴大豆球蛋白,设置不同的超高压条件对β-伴大豆球蛋白进行处理,利用免疫印迹法(Western-Blot)与ELISA法分析β-伴大豆球蛋白的免疫活性,通过SDS-PAGE、傅里叶变换红外光谱(FTIR)与荧光光谱表征β-伴大豆球蛋白的结构变化。结果表明:超高压处理能够显著改变β-伴大豆球蛋白的抗原性和结构。400 MPa超高压处理能最大程度地降低β-伴大豆球蛋白的免疫活性,且蛋白质二、三级结构发生显著变化,α-螺旋与β-转角含量下降,无规则卷曲和β-折叠含量上升,大量疏水性区域暴露。超高压处理改变了β-伴大豆球蛋白的空间结构,可能破坏或掩盖原有的抗原表位,进而降低抗原性。

Effect of high hydrostatic pressure treatment on the antigenicity and structure ofβ-conglycinin was studied to provide a method for the desensitization of soybean protein.In this study,β-conglycinin was extracted by using isoelectric point precipitation method and then processed under different high hydrostatic pressure conditions.The immunological activity ofβ-conglycinin was determined by Western-Blot and ELISA.SDS-PAGE,Fourier transform infrared spectroscopy and fluorescence spectroscopy were used to characterize the structure ofβ-conglycinin.The results showed that high hydrostatic pressure treatment significantly changed the antigenicity and structure ofβ-conglycinin.Under the pressure of 400 MPa,the immunological activity ofβ-conglycinin was minimized with significant change in the secondary and tertiary structures of protein.Contents ofα-helix andβ-turn were reduced,while contents ofβ-sheet and random coils were increased obviously,causing a large number of hydrophobic regions to be exposed.These results provide evidence that high hydrostatic pressure treatment changes the spatial structure ofβ-conglycinin,which may destroy or mask the original antigenic epitope,thereby lowering the antigenicity ofβ-conglycinin.