Inhibitory mechanism of angiotensin-converting enzyme inhibitory peptides from black tea

Novel Multitarget ACE Inhibitory Peptides from Bovine Colostrum Immunoglobulin G: Cellular Transport, Efficacy in Regulating Endothelial Dysfunction, and Network Pharmacology Studies

In this study, we used traditional laboratory methods, bioinformatics, and cellular models to screen novel ACE inhibitory (ACEI) peptides with strong ACEI activity, moderate absorption rates, and multiple targets from bovine colostrum immunoglobulin G (IgG). The purified fraction of the compound proteinase hydrolysate of IgG showed good ACEI activity. After nano-UPLC-MS/MS identification and in silico analysis, eight peptides were synthesized and verified. Among them, SFYPDY, TSFYPDY, FSWF, WYQQVPGSGL, and GVHTFP were identified as ACEI peptides, as they exhibited strong ACEI activity (with IC50 values of 104.7, 80.0, 121.2, 39.8, and 86.3 μM, respectively). They displayed good stability in an in vitro simulated gastrointestinal digestion assay. In a Caco-2 monolayer model, SFYPDY, FSWF, and WYQQVPGSGL exhibited better absorption rates and lower IC50 values than the other peptides and were thereby identified as novel ACEI peptides. Subsequently, in a H2O2-induced endothelial dysfunction (ED) model based on HUVECs, SFYPDY, FSWF, and WYQQVPGSGL regulated ED by reducing apoptosis and ROS accumulation while upregulating NOS3 mRNA expression. Network pharmacology analysis and RT-qPCR confirmed that they regulated multiple targets. Overall, our results suggest that SFYPDY, FSWF, and WYQQVPGSGL can serve as novel multitarget ACEI peptides.

Application of molecular dynamics simulation for exploring the roles of plant biomolecules in promoting environmental health

Understanding the dynamic changes of plant biomolecules is vital for exploring their mechanisms in the environment. Molecular dynamics (MD) simulation has been widely used to study structural evolution and corresponding properties of plant biomolecules at the microscopic scale. Here, this review (i) outlines structural properties of plant biomolecules, and the crucial role of MD simulation in advancing studies of the biomolecules; (ii) describes the development of MD simulation in plant biomolecules, determinants of simulation, and analysis parameters; (iii) introduces the applications of MD simulation in plant biomolecules, including the response of the biomolecules to multiple stresses, their roles in corrosive environments, and their contributions in improving environmental health; (iv) reviews techniques integrated with MD simulation, such as molecular biology, quantum mechanics, molecular docking, and machine learning modeling, which bridge gaps in MD simulation. Finally, we make suggestions on determination of force field types, investigation of plant biomolecule mechanisms, and use of MD simulation in combination with other techniques. This review provides comprehensive summaries of the mechanisms of plant biomolecules in the environment revealed by MD simulation and validates it as an applicable tool for bridging gaps between macroscopic and microscopic behavior, providing insights into the wide application of MD simulation in plant biomolecules.

Purification, molecular docking and in vivo analyses of novel angiotensin-converting enzyme inhibitory peptides from protein hydrolysate of moth bean (Vigna aconitifolia (Jacq.) Màrechal) seeds

The moth bean is a high-protein food legume. Enzymatic hydrolysates of food proteins demostrate health benefits. Search for diet related food protein hydrolysates is therefore within the scope of functional foods. Present study asertains to produce, screen and identify natural ACE-I inhibitory peptides derived from moth bean seed protein hydrolysates. The extracted protein was hydrolysed using alcalase, chymotrypsin, flavourzyme, papain, pepsin and trypsin respectively. Alcalase achieved the greatest degree of hydrolysis and ACE inhibition. The highest ACE-I inhibitory activity was exhibited by the peptide with the lowest molecular weight i.e. <3 kDa (IC₅₀ 11.19 ± 0.15 μg/mL). This was further separated by FPLC, followed by mass spectrometry. Molecular docking analysis showed the peptides IAWDFR and ADLPGLK bind to active sites whereas DKPWWPK and AVIPNAPNLR to non-active sites of the ACE molecule. In vivo administration of MBP hydrolysate to dexamethasone-induced hypertensive rats reduced their systolic blood pressure (125 ± 0.76 mmHg) compared with positive control (155 ± 3.13 mmHg). Moth bean protein peptides exhibit functional nutraceutical properties with adequate antihypertensive activity.

Structural characterization and angiotensin-converting enzyme (ACE) inhibitory mechanism of Stropharia rugosoannulata mushroom peptides prepared by ultrasound

To reveal the structural characteristics and angiotensin-converting enzyme (ACE) inhibition mechanism of Stropharia rugosoannulata mushroom peptides prepared by multifrequency ultrasound, the peptide distribution, amino acid sequence composition characteristics, formation pathway, and ACE inhibition mechanism of S. rugosoannulata mushroom peptides were studied. It was found that the peptides in S. rugosoannulata mushroom samples treated by multifrequency ultrasound (probe ultrasound and bath ultrasound mode) were mainly octapeptides, nonapeptides, and decapeptides. Hydrophobic amino acids were the primary amino acids in the peptides prepared by ultrasound, and the amino acid dissociation of the peptide bonds at the C-terminal under the action of ultrasound was performed mainly to produce hydrophobic amino acids. Pro and Val (PV), Arg and Pro (RP), Pro and Leu (PL), and Asp (D) combined with hydrophobic amino acids were the characteristic amino acid sequence basis of the active peptides of the S. rugosoannulata mushroom. The docking results of active peptides and ACE showed that hydrogen bond interaction remained the primary mode of interaction between ACE and peptides prepared by ultrasound. The peptides can bind to the amino acid residues in the ACE active pocket, zinc ions, or key amino acids in the domain, and this results in inhibition of ACE activity. Cation-pi interactions also played an important role in the binding of mushroom peptides to ACE. This study explains the structural characteristics and ACE inhibition mechanism used by S. rugosoannulata mushroom peptides prepared by ultrasound, and it will provide a reference for the development and application of S. rugosoannulata mushroom peptides.

Recent findings on the cellular and molecular mechanisms of action of novel food-derived antihypertensive peptides

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Hypertension has remained a silent-killer.

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Novel peptides recently isolated from food proteins.

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Molecular mechanism of blood pressure-lowering: renin and ACE-inhibition, and beyond.

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Proposed molecular mechanisms for future research.

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Novel peptides are excellent candidates for nutraceutical development.

Hypertension impacts negatively on the quality of life of sufferers, and complications associated with uncontrolled hypertension are life-threatening. Hence, many research efforts are exploring the antihypertensive properties of bioactive peptides derived from food proteins using in vitro ACE-inhibitory assay, experimentally-induced and spontaneous hypertensive rats, normotensive and hypertensive human models. In this study, the cellular and molecular mechanisms of blood pressure-lowering properties of novel peptides reported in recent studies (2015-July 30, 2021) were discussed. In addition to common mechanisms such as the inhibition of angiotensin I-converting enzyme (ACE) and renin activities, recently recognized mechanisms through which bioactive peptides exert their antihypertensive properties including the induction of vasodilation via upregulation of cyclo-oxygenase (COX) and prostaglandin receptor and endothelial nitric oxide synthase expression and L-type Ca²⁺ channel blockade were presented. Similarly, emerging mechanisms of blood pressure-lowering by bioactive peptides such as modulation of inflammation (TNF-α, and other cytokines signaling), oxidative stress (Keap-1/Nrf2/ARE/HO-1 and related signaling pathways), PPAR-γ/caspase3/MAPK signaling pathways and inhibition of lipid accumulation were discussed. The review also highlighted factors that influence the antihypertensive properties of peptides such as method of hydrolysis (type and number of enzymes, and chemical used for hydrolysis, and microbial fermentation), and amino acid sequence and chain length of peptides.

Formation and inhibition mechanism of novel angiotensin I converting enzyme inhibitory peptides from Chouguiyu

Angiotensin I converting enzyme (ACE) inhibitory peptides from fermented foods exhibit great potential to alleviate hypertension. In this study, the peptide extract from Chouguiyu exhibited a good inhibition effect on ACE, and the inhibition rate was significantly enhanced after fermentation for 8 days. The ACE inhibitory peptides were further identified, followed by their inhibition and formation mechanisms using microbiome technology and molecular docking. A total of 356 ACE inhibitory peptides were predicted using in silico, and most ACE inhibitory peptides increased after fermentation. These peptides could be hydrolyzed from 94 kinds of precursor proteins, mainly including muscle-type creatine kinase, nebulin, and troponin I. P1 (VEIINARA), P2 (FAVMVKG), P4 (EITWSDDKK), P7 (DFDDIQK), P8 (IGDDPKF), P9 (INDDPKIL), and P10 (GVDNPGHPFI) were selected as the core ACE inhibitory peptides according to their abundance and docking energy. The salt bridge and conventional hydrogen bond connecting unsaturated oxygen atoms in the peptides contributed most to the ACE inhibition. The cleavage proteases from the microbial genera in Chouguiyu for preparing these 7 core ACE inhibitory peptides were further analyzed by hydrolysis prediction and Pearson's correlation. The correlation network showed that P7, P8, and P9 were mainly produced by the proteases from LAB including Lactococcus, Enterococcus, Vagococcus, Peptostreptococcus, and Streptococcus, while P1, P2, P4, and P10 were mainly Produced by Aeromonas, Bacillus, Escherichia, and Psychrobacter. This study is helpful in isolating the proteases and microbial strains to directionally produce the responding ACE inhibitory peptides.