为探究湿热处理对花生球蛋白Ara h 3 抗原性的影响,采用硫酸铵分级沉淀法从花生脱脂粉中分离纯化出Ara h 3,进行不同温度、时间和质量浓度的湿热处理,通过正交试验确定最优湿热处理条件,采用间接 ELISA 法检测湿热处理后 Ara h 3 抗原性变化,测定外源荧光、游离巯基含量以及圆二色光谱,从蛋白结构的变化解释湿热处理对 Ara h 3 抗原性的影响.研究表明:湿热处理能够降低 Ara h 3抗原性,且在质量浓度 10 mg/mL、90℃处理 30 min时,抗原性降至最低;湿热处理后的Ara h 3 荧光强度、表面疏水性增强,三级结构发生变化;游离巯基含量增加、空间结构发生改变;α-螺旋和 β-折叠含量降低,无规则卷曲含量增加,二级结构发生变化.湿热处理后 Ara h 3 空间结构发生改变,部分抗原表位遭到破坏或被包埋,抗原性降低.
This study was aimed to explore the effect of damp-heat treatment on the antigenicity of peanut globulin Ara h 3.The Ara h 3 was purified from peanut defat powder by ammonium sulfate precipitation and treated by damp-heat at different temperatures,times and concentrations,and the optimal damp-heat treatment conditions were determined by orthogonal test.Indirect ELISA was used to detect the change of Ara h 3 antigenicity after damp-heat treatment,and the effect of damp-heat treatment on the Ara h 3 was determined by measuring exogenous fluorescence,free sulfhydryl groups,and circular dichroism spectra.The experimental results showed that the damp-heat treatment could reduce the antigenicity of Ara h 3,and the antigenicity of Ara h 3 solution was minimized at 10 mg/mL and treated at 90℃for 30 min.After damp-heat treatment,the fluorescence intensity and surface hydrophobicity of Ara h 3 were enhanced,and the tertiary structure changed;the content of free sulfhydryl was increased,and the spatial structure changed;the content of α-helix and β-fold decreased,irregular coil content increased,and the secondary structure changed.After damp-heat treatment,the spatial structure of Ara h 3 was changed,and some of its epitopes were destroyed or buried,reducing its antigenicity.