大米谷蛋白模拟酶解释放生物活性肽的研究

目的 通过对大米谷蛋白的模拟酶解及生物信息学分析, 评价大米谷蛋白作为生物活性肽前体的潜在价值。方法 首先, 利用计算机在UniProt蛋白质数据库中查找大米谷蛋白的序列, 使用BIOPEP活性肽数据库对所选的3条序列进行模拟酶解, 并同时对酶解产生的肽片段数量、分子量及其氨基酸组成进行统计分析。然后, 将模拟酶解产生的肽片段序列与BIOPEP数据库中已有记载的生物活性肽序列进行对比, 筛选出具有生物活性的肽片段。最后, 对模拟酶解产生的生物活性肽进行致敏性和毒性预测。结果 胃蛋白酶和木瓜蛋白酶是最适合水解大米谷蛋白的两种酶。大米谷蛋白酶解可产生许多生物活性肽, 其中出现频率最高的是二肽基肽酶Ⅳ (dipeptidyl peptidase-IV, DPP-IV)抑制肽和血管紧张素转换酶(angiotensin-converting enzyme, ACE)抑制肽。大米谷蛋白本身无潜在致敏性, 且其经过计算机模拟酶解得到的DPP-IV抑制肽和ACE抑制肽均无细胞毒性。结论 大米谷蛋白可作为酶解释放DPP-IV抑制肽和ACE抑制肽的良好前体, 本研究为大米谷蛋白酶解生产生物活性肽提供了理论指导。

Study on release of bioactive peptides from rice glutelin by in silico enzymatic hydrolysis

Objective To evaluate the potential value of rice glutelin as bioactive peptide precursor, through silico enzymatic hydrolysis and bioinformatics analysis of rice glutelin. Methods First, the rice glutenin sequences were searched in the UniProt protein database by computer, and the 3 selected sequences were subjected to silico enzymatic hydrolysis by using the BIOPEP active peptide database, and the number, molecular weight and amino acid composition of peptide fragments generated by enzymatic hydrolysis were statistically analyzed. Then, the peptide fragments sequence generated from in silico enzymatic hydrolysis was compared with the bioactive peptide sequence recorded in the BIOPEP database to screen out the peptide fragment with biological activity. Finally, the allergenicity and toxicity of the bioactive peptides generated from in silico enzymatic hydrolysis were predicted. Results Pepsin and papain were the 2 most suitable enzymes for the hydrolysis of rice glutelin. Rice glutelin hydrolysis could produce many bioactive peptides, and the dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides and angiotensin-converting enzyme (ACE) inhibitory peptides showed the highest frequency. The rice glutenin itself had no potential sensitization, and neither the DPP-IV inhibitory peptide nor the ACE inhibitory peptide obtained from in silico enzymatic hydrolysis had cytotoxicity. Conclusion Rice glutelin can be used as a good precursor for enzymatic hydrolysis of DPP-IV inhibitory peptides and ACE inhibitory peptides. This study provides theoretical guidance for enzymatic hydrolysis of rice glutelin to produce bioactive peptides.