Li Yan, Yang Yong, Feng Chen, Liu Jie, Wang Jing, Wang Luchen
Food Science College of Shanxi Normal University, Taiyuan, 030031, China.
Shanxi Normal University, Taiyuan, 030092, China.
Plant Foods Hum Nutr. 2025 Apr 10;80(2):109. doi: 10.1007/s11130-025-01352-5.
Camellia oleifera expeller is an abundant protein resource, but its usage in food is limited. In this study, potential antioxidant and hypotensive peptides with ferrous-chelating activity were isolated, identified, and virtually screened from camellia expeller globulin hydrolysates. The action mechanisms against Keap1 and angiotensin-I-converting enzyme (ACE), gastrointestinal stability, and ferrous-transmembrane absorption were studied. After in silico screening, a safe multifunctional octapeptide: Ser-Gly-Tyr-Gly-Tyr-Gly-Tyr-Gly (SGYGYGYG) was obtained. SGYGYGYG showed high ACE-restraining ability of IC:89.44 µmol/L (equivalent to that of Valsartan), ferrous chelating (8.67 mg/g) and hydroxyl radical quenching abilities (93.06%). SGYGYGYG can inhibit the Keap1-Nrf2 interaction by binding to 9 residues of Keap1; and it bound to key sites in ACE's linking (Tyr523, Gln281, Lys511, and Ala354) and catalytic centre (His353 and His383). SGYGYGYG's phenolic hydroxyl, amino, and carboxyl groups had strong affinity for ferrous ions. Ferrous chelation did not alter ACE-inhibition capacity and model of SGYGYGYG, but reduced its hydroxyl and ABTS radical quenching ability (p < 0.05). Moreover, the intestinal stability and transmembrane absorption of ferrous ions were improved by SGYGYGYG-ferrous chelate, though SGYGYGYG had poor gastrointestinal stability. Thus, SGYGYGYG may be exploited as ingredients of hypotensive, antioxidant, and iron supplementary agents.
油茶籽压榨饼是一种丰富的蛋白质资源，但其在食品中的应用有限。在本研究中，从油茶籽球蛋白水解物中分离、鉴定并虚拟筛选出具有亚铁螯合活性的潜在抗氧化和降血压肽。研究了其对Keap1和血管紧张素转换酶（ACE）的作用机制、胃肠道稳定性以及亚铁跨膜吸收。经过计算机筛选，获得了一种安全的多功能八肽：Ser-Gly-Tyr-Gly-Tyr-Gly-Tyr-Gly（SGYGYGYG）。SGYGYGYG表现出高ACE抑制能力，IC50为89.44 μmol/L（相当于缬沙坦），亚铁螯合能力（8.67 mg/g）和羟基自由基淬灭能力（93.06%）。SGYGYGYG可通过与Keap1的9个残基结合来抑制Keap1-Nrf2相互作用；并且它与ACE连接位点（Tyr523、Gln281、Lys511和Ala354）和催化中心（His353和His383）的关键位点结合。SGYGYGYG的酚羟基、氨基和羧基对亚铁离子具有很强的亲和力。亚铁螯合不会改变SGYGYGYG的ACE抑制能力和模式，但会降低其羟基和ABTS自由基淬灭能力（p < 0.05）。此外，尽管SGYGYGYG的胃肠道稳定性较差，但SGYGYGYG-亚铁螯合物可改善亚铁离子的肠道稳定性和跨膜吸收。因此，SGYGYGYG可被开发用作降血压、抗氧化和补铁剂的成分。
