Wu Qiongying, Du Jinjuan, Jia Junqiang, Kuang Cong
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, China.
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China.
Food Chem. 2016 May 15;199:140-9. doi: 10.1016/j.foodchem.2015.12.012. Epub 2015 Dec 7.
In this study, sweet sorghum grain protein (SSGP) was hydrolyzed using alcalase yielding ACE inhibitory peptides. A kinetic model was proposed to describe the enzymolysis process of SSGP. The kinetic parameters, a and b, were determined according to experimental data. It was found that the model was reliable to describe the kinetic behaviour for SSGP hydrolysis by alcalase. After hydrolysis, the SSGP hydrolysate with DH of 19% exhibited the strongest ACE inhibitory activity and the hydrolysate was then used to isolate ACE inhibitory peptides. A novel ACE inhibitory peptide was successfully purified from this hydrolysate by ultrafiltration, ion exchange chromatography, gel filtration chromatography, and reversed-phased high performance liquid chromatography (RP-HPLC). The amino acid sequence of the purified peptide was identified as Thr-Leu-Ser (IC50=102.1 μM). The molecular docking studies revealed that the ACE inhibition of the tripeptide was mainly attributed to its C-terminal Ser, which can effectively interact with the S1 and S2 pockets of ACE. Our studies suggest that the tripeptide from the SSGP hydrolysate can be utilized to develop functional food ingredients or pharmaceuticals for prevention of hypertension.
在本研究中，使用碱性蛋白酶水解甜高粱籽粒蛋白（SSGP）以产生具有血管紧张素转换酶（ACE）抑制活性的肽。提出了一个动力学模型来描述SSGP的酶解过程。根据实验数据确定了动力学参数a和b。结果发现该模型能够可靠地描述碱性蛋白酶水解SSGP的动力学行为。水解后，水解度为19%的SSGP水解产物表现出最强的ACE抑制活性，然后用该水解产物分离ACE抑制肽。通过超滤、离子交换色谱、凝胶过滤色谱和反相高效液相色谱（RP-HPLC）从该水解产物中成功纯化出一种新型ACE抑制肽。纯化肽的氨基酸序列鉴定为苏氨酸-亮氨酸-丝氨酸（IC50 = 102.1 μM）。分子对接研究表明，该三肽对ACE的抑制作用主要归因于其C端的丝氨酸，它可以与ACE的S1和S2口袋有效相互作用。我们的研究表明，来自SSGP水解产物的三肽可用于开发功能性食品成分或预防高血压的药物。
