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

2021 ◽  
Vol 8 ◽  
Author(s):  
Zeqi He ◽  
Guo Liu ◽  
Zijiao Qiao ◽  
Yong Cao ◽  
Mingyue Song

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.

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Wei Wang ◽  
Nan Wang ◽  
Yu Zhang ◽  
Zheng Cai ◽  
Qihe Chen ◽  
...  

A convenient and accurate reversed-phase high-performance liquid chromatography (RP-HPLC) method for angiotensin I-converting enzyme inhibitory peptides assay was described in this paper. The mobile phase consisted of 70% A (0.05% TFA and 0.05% triethylamine in water, pH = 2.9–3.3) and 30% B (100% acetonitrile) using an Isogradient program. The flow rate was 0.5 mL/min. The absorb wavelength was 226.5 nm; the column temperature was controlled at 25°C. This method for angiotensin I-converting enzyme inhibitory peptides assay was convenient for the Iso-gradient program. The accuracy of the RT-HPLC method was verified by analyzing ACE inhibitory activity of the hydrolysate peptides of silkworm pupae protein, and the results showed that the RT-HPLC method was available for exploring new source of angiotensin I-converting enzyme inhibitory peptides rapidly and veraciously.


1998 ◽  
Vol 330 (1) ◽  
pp. 61-65 ◽  
Author(s):  
R. Elwyn ISAAC ◽  
Liliane SCHOOFS ◽  
A. Tracy WILLIAMS ◽  
Dirk VEELAERT ◽  
Mohammed SAJID ◽  
...  

Insect peptidyl-dipeptidase A [angiotensin I-converting enzyme (ACE)] is a soluble single-domain peptidyl-dipeptidase that has many properties in common with the C-domain of mammalian somatic ACE and with the single-domain mammalian germinal ACE. Mammalian somatic ACE is important in blood homoeostasis, but the role of ACE in insects is not known. Immunocytochemistry has been used to localize ACE in the neuroendocrine system of the locust, Locusta migratoria. Staining was observed in five groups of neurosecretory cells in the brain and suboesophageal ganglion, in the nervi corpori cardiaci, the storage part of the corpora cardiaca and in the nervi corpori allati. In three groups of neurosecretory cells, ACE co-localized with locustamyotropins, suggesting a possible role for the enzyme in the metabolism of these neuropeptides. We demonstrate in vitro a novel activity of ACE that removes pairs of basic amino acid residues from a locustamyotropin peptide extended at the C-terminus with either Gly-Lys-Arg or Gly-Arg-Arg, corresponding to a consensus recognition sequence for endoproteolysis of prohormone proteins by prohormone convertases. The low Km and high kcat values (Km 7.3 and 5.0 μM, kcat 226 and 207 s-1 for the hydrolysis of Phe-Ser-Pro-Arg-Leu-Gly-Lys-Arg and Phe-Ser-Pro-Arg-Leu-Gly-Arg-Arg, respectively) obtained for the hydrolysis of these two peptides by insect ACE means that these peptides, along with mammalian bradykinin, are the most favoured in vitro ACE substrates so far identified. The discovery of this in vitro prohormone-processing activity of insect ACE provides a possible explanation for the intracellular co-localization of the enzyme with locustamyotropin peptides, and provides evidence for a new role for ACE in the biosynthesis of peptide hormones and transmitters.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1746 ◽  
Author(s):  
Ning Li ◽  
Aimin Shi ◽  
Qiang Wang ◽  
Guoquan Zhang

The multivesicular liposome (MVL) provides a potential delivery approach to avoid the destruction of the structure of drugs by digestive enzymes of the oral cavity and gastrointestinal system. It also serves as a sustained-release drug delivery system. In this study, we aimed to incorporate a water-soluble substance into MVLs to enhance sustained release, prevent the destruction of drugs, and to expound the function of different components and their mechanism. MVLs were prepared using the spherical packing model. The morphology, structure, size distribution, and zeta potential of MVLs were examined using an optical microscope (OM), confocal microscopy (CLSM), transmission electron cryomicroscope (cryo-EM) micrograph, a Master Sizer 2000, and a zeta sizer, respectively. The digestion experiment was conducted using a bionic mouse digestive system model in vitro. An in vitro release and releasing mechanism were investigated using a dialysis method. The average particle size, polydispersity index, zeta potential, and encapsulation efficiency are 47.6 nm, 1.880, −70.5 ± 2.88 mV, and 82.00 ± 0.25%, respectively. The studies on the controlled release in vitro shows that MVLs have excellent controlled release and outstanding thermal stability. The angiotensin I-converting enzyme (ACE) inhibitory activity of ACE-inhibitory peptide (AP)-MVLs decreased only 2.84% after oral administration, and ACE inhibitory activity decreased by 5.03% after passing through the stomach. Therefore, it could serve as a promising sustained-release drug delivery system.


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