Peptides derived from food proteins have exhibited significant antihypertensive effects without side effects. In this study, the cottonseed protein was hydrolyzed by papain for preparing peptide wi...

https://www.tandfonline.com/doi/pdf/10.1080/10942912.2019.1640735

Isolation and identification of the angiotensin-I converting enzyme (ACE) inhibitory peptides derived from cottonseed protein: optimization of hydrolysis conditions

Identification and molecular mechanism of angiotensin-converting enzyme inhibitory peptides from Larimichthys crocea titin

To effectively utilize skipjack tuna (Katsuwonus pelamis) processing by-products to prepare peptides with high angiotensin-I-converting enzyme (ACE) inhibitory (ACEi) activity, Neutrase was selected from five kinds of protease for hydrolyzing skipjack tuna dark muscle, and its best hydrolysis conditions were optimized as enzyme dose of 1.6%, pH 6.7, and temperature of 50°C using single factor and response surface experiments. Subsequently, 14 novel ACEi peptides were prepared from the high ACEi protein hydrolysate and identified as TE, AG, MWN, MEKS, VK, MQR, MKKS, VKRT, IPK, YNY, LPRS, FEK, IRR, and WERGE. MWN, MEKS, MKKS, and LPRS displayed significantly ACEi activity with IC50 values of 0.328 ± 0.035, 0.527 ± 0.030, 0.269 ± 0.006, and 0.495 ± 0.024 mg/mL, respectively. Furthermore, LPRS showed the highest increasing ability on nitric oxide (NO) production among four ACEi peptides combining the direct increase and reversing the negative influence of norepinephrine (NE), and MKKS showed the highest ability on directly decreasing and reversing the side effects of NE on the secretion level of endothelin-1 (ET-1) among four ACEi peptides. These findings demonstrate that seafood by-product proteins are potential ACEi peptide sources and prepared ACEi peptides from skipjack tuna dark muscle, which are beneficial components for functional food against hypertension and cardiovascular diseases.

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Preparation, Characterization, and Cytoprotective Effects on HUVECs of Fourteen Novel Angiotensin-I-Converting Enzyme Inhibitory Peptides From Protein Hydrolysate of Tuna Processing By-Products

Seaweeds are a typical food of East-Asian cuisine, to which are alleged several beneficial health effects have been attributed. Their availability and their nutritional and chemical composition have favored the increase in its consumption worldwide, as well as a focus of research due to their bioactive properties. In this regard, seaweed proteins are nutritionally valuable and comprise several specific enzymes, glycoproteins, cell wall-attached proteins, red algae phycobiliproteins, lectins, peptides, or mycosporine-like amino acids. This great extent of molecules has been reported to exert significant antioxidant, antimicrobial, anti-inflammatory, antihypertensive, antidiabetic, or antitumoral properties. Hence, knowledge on algae proteins and derived compounds have gained special interest for the potential nutraceutical, cosmetic or pharmaceutical industries based on these bioactivities. Although several molecular mechanisms of action on how these proteins and peptides exert biological activities have been described, many gaps in knowledge still need to be filled. Updating the current knowledge related to seaweed proteins and peptides is of interest to further asses their potential health benefits. This review addresses the characteristics of seaweed protein and protein-derived molecules, their natural occurrence, their studied bioactive properties, and their described potential mechanisms of action.

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Seaweed-Derived Proteins and Peptides: Promising Marine Bioactives

The bioactive peptides that can inhibit angiotensin-I converting enzyme (ACE, EC. 3. 4.15.1) are considered as possible cures of hypertension. Food-derived angiotensin-I converting enzyme inhibitory (ACEi) peptides have gained more attention because of their reduced side effects. In this study, we reported the method for purifying ACEi peptides from the lees of traditional Chinese rice wine and evaluated the product's biochemical properties. After three steps of reversed-phase high-performance liquid chromatography (RP-HPLC), for the first time, we isolated, purified, and identified two novel peptides: LIIPQH and LIIPEH, both of which showed strong ACEi activity (IC50-values of 120.10 ± 9.31 and 60.49±5.78 μg/ml, respectively). They were further categorized as mixed-type ACE inhibitors and were stable against both ACE and gastrointestinal enzymes during in vitro digestion. Together, these results suggest that the rice wine lees that produced as a by-product during rice wine production can be utilized in various fields related to functional foods and antihypertensive medicine.

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Novel Angiotensin-I Converting Enzyme Inhibitory Peptides Isolated From Rice Wine Lees: Purification, Characterization, and Structure-Activity Relationship.

Angiotensin-I-converting enzyme (ACE) inhibitory peptides derived from marine organism have shown a blood pressure lowering effect with no side effects. A new affinity medium of Fe3O4@ZIF-90 immobilized ACE (Fe3O4@ZIF-90-ACE) was prepared and used in the purification of ACE inhibitory peptides from Wakame (Undaria pinnatifida) protein hydrolysate (<5 kDa). The Fe3O4@ZIF-90 nanoparticles were prepared by a one-pot synthesis and crude ACE extract from pig lung was immobilized onto it, which exhibited excellent stability and reusability. A novel ACE inhibitory peptide, KNFL (inhibitory concentration 50, IC50 = 225.87 μM) was identified by affinity purification using Fe3O4@ZIF-90-ACE combined with reverse phase-high performance liquid chromatography (RP-HPLC) and MALDI-TOF mass spectrometry. Lineweaver–Burk analysis confirmed the non-competitive inhibition pattern of KNFL, and molecular docking showed that it bound at a non-active site of ACE via hydrogen bonds. This demonstrates that affinity purification using Fe3O4@ZIF-90-ACE is a highly efficient method for separating ACE inhibitory peptides from complex protein mixtures and the purified peptide KNFL could be developed as a functional food ingredients against hypertension.

https://www.mdpi.com/1660-3397/19/3/177/pdf

Affinity Purification of Angiotensin Converting Enzyme Inhibitory Peptides from Wakame (Undaria Pinnatifida) Using Immobilized ACE on Magnetic Metal Organic Frameworks.

Casein proteins were hydrolyzed by papain to identify inhibitory peptides of angiotensin I-converting enzyme (ACE). The hydrolysate was fractionized by immobilized metal affinity chromatography (IMAC-Ni2+). The fraction with high ACE inhibitory activity was enriched and further chromatographed on a reverse-phase column to yield four fractions. Among the fractions, the L4 fraction exhibited the highest ACE inhibitory activity and was identified by sequence analysis as Trp-Tyr-Leu-His-Tyr-Ala (WYLHYA), with IC50 value of 16.22 ± 0.83 µM in vitro. This peptide was expected to be applied as an ingredient for preventing hypertension and IMAC-Ni2+ may provide a simple method for purification of ACE inhibitory peptides.

Purification of angiotensin I-converting enzyme (ACE) inhibitory peptides from casein hydrolysate by IMAC-Ni 2+

Separation and identification of ACE inhibitory peptides from lizard fish proteins hydrolysates by metal affinity-immobilized magnetic liposome.

A metal affinity-immobilized magnetic liposome (MA-IML) was prepared in this research, which was with lipid and Ni2+ content of 143.25 μg/mg and 32 μmol/mg, respectively. The antihypertensive peptides Ile-Pro-Pro (IPP) and Val-Pro-Pro (VPP) could be adsorbed onto MA-IML under specific conditions, and the adsorption kinetics was explored. The pseudo-second-order kinetics ( ) was more suitable to describe the adsorption process of IPP and VPP than the intraparticle diffusion model and pseudo-first-order kinetic model. The results indicated that MA-IML could be used as an adsorbent for screening antihypertensive peptides from natural products.

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Development and Adsorption Characterization of Metal Affinity-Immobilized Magnetic Liposome

The invention provides a preparation method of N-alkyl iminodiacetic acid The N-alkyl iminodiacetic acid has the structural formula as shown in the specification The preparation method provided by the invention comprises the following steps: taking aliphatic amine and ethyl bromoacetate as raw materials, carrying out hydrolysis and acidification directly after reacting to obtain a crude productand then recrystallizing to obtain a pure product By adopting the preparation process, the synthetic route is short, the operation is simple, and the yield and the purity of the product are higher The compound synthesized by the method can be used as a surfactant and an intermediate for synthesizing other medicines

Yuan Lu

Papers

Affinity Purification of Angiotensin Converting Enzyme Inhibitory Peptides from Wakame (Undaria Pinnatifida) Using Immobilized ACE on Magnetic Metal Organic Frameworks.

Purification of angiotensin I-converting enzyme (ACE) inhibitory peptides from casein hydrolysate by IMAC-Ni 2+

Separation and identification of ACE inhibitory peptides from lizard fish proteins hydrolysates by metal affinity-immobilized magnetic liposome.

Development and Adsorption Characterization of Metal Affinity-Immobilized Magnetic Liposome

Preparation method of N-alkyl iminodiacetic acid