加热联合酶解大豆7S蛋白的分子结构及抗原性研究

Molecular structure and antigenicity analysis of enzymatic hydrolysates from soybean 7S globulin by heating and protease treatment

选用不同加热预处理条件、不同蛋白酶处理大豆7S蛋白,SDS-PAGE考察酶解后大豆7S蛋白的降解情况,间接竞争ELISA法考察酶解物的抗原性。结果表明:加热预处理联合酶解可显著增大β-伴大豆球蛋白的降解程度,β亚基消化程度得到极大提升,α亚基、α’亚基几乎完全被降解,在相同酶解时间下,胰蛋白酶的酶解速度快于胃蛋白酶;加热预处理联合酶解大幅降低了β-伴大豆球蛋白的抗原性,胰蛋白酶的效果优于胃蛋白酶,经80℃加热10 min预处理再经胰蛋白酶处理,大豆7S蛋白的抗原性降低了79.99%,而胃蛋白酶最优条件下最多仅降低50.4%;SDSPAGE结果表明,胃蛋白酶、胰蛋白酶酶解物中出现了抗消化肽段,经过质谱鉴定,均来自于β-伴大豆球蛋白的α亚基。

Soybean 7 S globulin was hydrolyzed with different proteases under different heating pretreatment conditions.SDS-PAGE was used to investigate the degradation of soybean 7 S globulin after enzymatic hydrolysis.Indirect competitive ELISA was used to detect the antigenicity of the hydrolysates.The results showed that the heating pretreatment combined with enzymatic hydrolysis could significantly increase the degradation ofβ-conglycinin.The digestibility of theβsubunit was greatly improved and theαsubunit and theα’subunit were almost completely degraded.The enzymatic hydrolysis rate of trypsin was faster than that of pepsin at the same enzymatic hydrolysis time.Heating pretreatment combined with enzymatic hydrolysis could significantly reduce the antigenicity ofβ-conglycinin and the effect of trypsin was better than that of pepsin.Meanwhile,heating at 80℃for 10 min followed by trypsin hydrolysis treatment could decrease the antigenicity of soybean 7S globulin by 79.99%,while pepsin only could decrease by 50.4%under the optimal condition.SDS-PAGE results showed that the antidigestible fragments derived from the hydrolysates by pepsin and trypsin were derived from theαsubunit ofβ-conglycinin,which was identified by mass spectrometry.