scholarly journals Effect of temperature and chloride on steady-state inhibition of angiotensin I-converting enzyme by enalaprilat and ramiprilat

1990 ◽  
Vol 272 (2) ◽  
pp. 415-419 ◽  
Author(s):  
A Skoglof ◽  
P O Göthe ◽  
J Deinum
Keyword(s):  
Steady State ◽  
Amino Acid ◽  
Protein Concentration ◽  
Chloride Concentration ◽  
Effect Of Temperature ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Inhibitor Binding ◽  
Angiotensin I Converting Enzyme ◽  
Kinetics Of

The kinetics of the steady-state inhibition of angiotension I-converting enzyme (EC 3.4.15.1) at 25 degrees C and 37 degrees C with enalaprilat and ramiprilat can be simulated, assuming only one inhibitor-binding site, consistent with a 1:1 stoichiometry if the protein concentration was determined by amino acid analysis. In this temperature range the apparent inhibition constants for ramiprilat and enalaprilat were roughly doubled by a decrease in the chloride concentration from 0.300 M to 0.120 M.

Yak Milk Casein as a Functional Ingredient: Preparation and Identification of Angiotensin-I-Converting Enzyme Inhibitory Peptides

2006 ◽  
Vol 74 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Jingli Jiang ◽  
Shangwu Chen ◽  
Fazheng Ren ◽  
Zhang Luo ◽  
Steve S Zeng
Keyword(s):  
Amino Acid ◽  
Inhibitory Activity ◽  
Value Added ◽  
Amino Acid Sequences ◽  
Food Protein ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Yak Milk ◽  
Angiotensin I Converting Enzyme ◽  
Milk Casein

Yak milk casein derived from Qula, a traditional Tibetan acid curd cheese, was hydrolyzed by six commercially available proteases (Trypsin, Pepsin, Alcalase, Flavourzyme, Papain and Neutrase). These hydrolysates were assayed for their inhibitory activity of Angiotensin-I-converting enzyme (ACE). The hydrolysates obtained by Neutrase from Bacillus amyloliquefaciens showed the highest ACE inhibitory activity. The IC50 value of Neutrase-hydrolysate was 0·38 mg/ml. The hydrolysate obtained by Neutrase was further separated by consecutive ultra-filtration with 10 kDa and then with 6 kDa molecular weight cut-offs into different permeated parts and fractionated by gel filtration chromatography with a Sephadex G-25 column. The active fraction was subjected to RP-HPLC, in which five peaks were purified and identified. Amino acid sequence analysis confirmed that the peptides and origins were as follows: YQKFPQY (αs2-CN; f89–95), LPQNIPPL (β-CN; f70–77), SKVLPVPQK (β-CN; f168–176), LPYPYY (κ-CN; f56–61) and FLPYPYY (κ-CN; f55–61). Their amino acid sequences matched well with those of known bioactive peptides from bovine casein. The results indicated that yak milk casein could be a resource to generate antihypertensive peptides and be used as multifunctional active ingredients for many value-added functional foods as well as a traditional food protein.

scholarly journals The analysis of Angiotensin-I Converting Enzyme (ACE) by maitake (Grifrola frondosa) mycelia

2021 ◽  
Vol 8 (2) ◽  
pp. 69-72
Author(s):  
Yuen Sim Kheng ◽  
Young Liew Jeng ◽  
Maryana Mohamad Nor ◽  
Geng Boon Jia
Keyword(s):  
Inhibitory Activity ◽  
Protein Concentration ◽  
Bioactive Peptides ◽  
Biological Properties ◽  
Degree Of Hydrolysis ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Hydrolysis Time ◽  
Angiotensin I Converting Enzyme ◽  
Freeze Dried

The Maitake (Grifola frondosa) is useful in treating diseases, specifically hypertension. Research on the maitake mycelia’s biological properties, nevertheless, are limited in the literature. This study aimed to (i) produce mushroom biomass adopting submerged fermentation, and (ii) investigate the Angiotensin-I Converting Enzyme inhibitory activity. Maitake mycelia’s yield after 14 days of fermentation under controlled conditions (approx. 1.32 g/L) were freeze-dried into powder and later were hydrolysed for analyses of Angiotensin-I Converting Enzyme inhibitory activity. Current results showed that the degree of hydrolysis increased in line with hydrolysis time, as the protein concentration for hydrolysed sample was 283.61 ± 7.14 µg/mL, however, the non-hydrolysed sample resulted in lesser protein content (46.76 ± 1.09 µg/mL). The hydrolysate maitake mycelia has higher Angiotensin-I Converting Enzyme inhibitory activity (46.48%) as compared to the non-hydrolysate maitake mycelia (20.19 ± 0.17%). This finding suggested maitake mycelia hydrolysate can be a source of potential bioactive peptides used in treating hypertension.

scholarly journals Drosophila melanogaster angiotensin I-converting enzyme expressed in Pichia pastoris resembles the C domain of the mammalian homologue and does not require glycosylation for secretion and enzymic activity

1996 ◽  
Vol 318 (1) ◽  
pp. 125-131 ◽  
Author(s):  
Tracy A. WILLIAMS ◽  
Annie MICHAUD ◽  
Xavier HOUARD ◽  
Marie-Thérèse CHAUVET ◽  
Florent SOUBRIER ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Pichia Pastoris ◽  
Ace Inhibitors ◽  
Active Sites ◽  
Chloride Concentration ◽  
Enzymic Activity ◽  
Expression Level ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Angiotensin I Converting Enzyme

Drosophila melanogaster angiotensin I-converting enzyme (AnCE) is a secreted single-domain homologue of mammalian angiotensin I-converting enzyme (ACE) which comprises two domains (N and C domains). In order to characterize in detail the enzymic properties of AnCE and to study the influence of glycosylation on the secretion and enzymic activity of this enzyme, we overexpressed AnCE (expression level, 160 mg/l) and an unglycosylated mutant (expression level, 43 mg/l) in the yeast Pichia pastoris. The recombinant enzyme was apparently homogeneous on SDS/PAGE without purification and partial deglycosylation demonstrated that all three potential sites for N-linked glycosylation were occupied by oligosaccharide chains. Each N-glycosylation sequence (Asn-Xaa-Ser/Thr) was disrupted by substituting a glutamine for the asparagine residue at amino acid positions 53, 196 and 311 by site-directed mutagenesis to produce a single mutant. Expression of the unglycosylated mutant in Pichia produced a secreted catalytically active enzyme (AnCEΔCHO). This mutant displayed unaltered kinetics for the hydrolyses of hippuryl-His-Leu, angiotensin I and N-acetyl-Ser-Asp-Lys-Pro (AcSDKP) and was equally sensitive to ACE inhibitors compared with wild-type AnCE. However, AnCEΔCHO was less stable, displaying a half-life of 4.94 h at 37 °C, compared with AnCE which retained full activity under the same conditions. Two catalytic criteria demonstrate the functional resemblance of AnCE with the human ACE C domain: first, the kcat/Km of AcSDKP hydrolysis and secondly, the kcat/Km and optimal chloride concentration for hippuryl-His-Leu hydrolysis. A range of ACE inhibitors were far less potent towards AnCE compared with the human ACE domains, except for captopril which suggests an alternative structure in AnCE corresponding to the region of the S1 subsite in the human ACE active sites.

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