Zhejiang Provincial Engineering Technology Research Center of Marine Biomedical Products, School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China.
National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, School of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China.
Mar Drugs. 2023 Sep 28;21(10):516. doi: 10.3390/md21100516.
The objective of this study was to isolate and characterize collagen and angiotensin-I-converting enzyme (ACE)-inhibitory (ACEi) peptides from the swim bladders of monkfish (). Therefore, acid-soluble collagen (ASC-M) and pepsin-soluble collagen (PSC-M) with yields of 4.27 ± 0.22% and 9.54 ± 0.51%, respectively, were extracted from monkfish swim bladders using acid and enzyme methods. The ASC-M and PSC-M contained Gly (325.2 and 314.9 residues/1000 residues, respectively) as the major amino acid, but they had low imino acid content (192.5 and 188.6 residues/1000 residues, respectively) in comparison with collagen from calf skins (CSC) (216.6 residues/1000 residues). The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns and ultraviolet (UV) absorption spectrums of ASC-M and PSC-M illustrated that they were mainly composed of type I collagen. Subsequently, three ACEi peptides were isolated from a PSC-M hydrolysate prepared via a double-enzyme system (alcalase + neutrase) and identified as SEGPK (MHP6), FDGPY (MHP7) and SPGPW (MHP9), with molecular weights of 516.5, 597.6 and 542.6 Da, respectively. SEGPK, FDGPY and SPGPW displayed remarkable anti-ACE activity, with IC values of 0.63, 0.94 and 0.71 mg/mL, respectively. Additionally, a molecular docking assay demonstrated that the affinities of SEGPK, FDGPY and SPGPW with ACE were -7.3, -10.9 and -9.4 kcal/mol, respectively. The remarkable ACEi activity of SEGPK, FDGPY and SPGPW was due to their connection with the active pockets and/or sites of ACE via hydrogen bonding, hydrophobic interaction and electrostatic force. Moreover, SEGPK, FDGPY and SPGPW could protect HUVECs by controlling levels of nitric oxide (NO) and endothelin-1 (ET-1). Therefore, this work provides an effective means for the preparation of collagens and novel ACEi peptides from monkfish swim bladders, and the prepared ACEi peptides, including SEGPK, FDGPY and SPGPW, could serve as natural functional components in the development of health care products to control hypertension.
本研究的目的是从安康鱼肝中分离并鉴定胶原蛋白和血管紧张素转化酶（ACE）抑制肽（ACEi）。因此，采用酸法和酶法从安康鱼肝中分别提取酸溶性胶原蛋白（ASC-M）和胃蛋白酶溶性胶原蛋白（PSC-M），得率分别为 4.27±0.22%和 9.54±0.51%。ASC-M 和 PSC-M 中的主要氨基酸分别为甘氨酸（325.2 和 314.9 残基/1000 残基），但与小牛皮胶原蛋白（CSC）（216.6 残基/1000 残基）相比，其亚氨基酸含量较低（分别为 192.5 和 188.6 残基/1000 残基）。ASC-M 和 PSC-M 的十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）图谱和紫外（UV）吸收光谱表明，它们主要由 I 型胶原蛋白组成。随后，从双酶系统（碱性蛋白酶+中性蛋白酶）制备的 PSC-M 水解物中分离出三种 ACEi 肽，并鉴定为 SEGPK（MHP6）、FDGPY（MHP7）和 SPGPW（MHP9），分子量分别为 516.5、597.6 和 542.6 Da。SEGPK、FDGPY 和 SPGPW 均具有显著的 ACE 抑制活性，IC50 值分别为 0.63、0.94 和 0.71mg/mL。此外，分子对接试验表明，SEGPK、FDGPY 和 SPGPW 与 ACE 的亲和力分别为-7.3、-10.9 和-9.4kcal/mol。SEGPK、FDGPY 和 SPGPW 具有显著的 ACEi 活性，是由于它们通过氢键、疏水相互作用和静电力与 ACE 的活性口袋和/或位点结合。此外，SEGPK、FDGPY 和 SPGPW 可以通过控制一氧化氮（NO）和内皮素-1（ET-1）的水平来保护人脐静脉内皮细胞（HUVECs）。因此，本研究为从安康鱼肝中制备胶原蛋白和新型 ACEi 肽提供了一种有效的方法，所制备的 ACEi 肽，包括 SEGPK、FDGPY 和 SPGPW，可作为开发保健品以控制高血压的天然功能成分。
