Kinetics Study of Protein Hydrolysis and Inhibition of Angiotensin Converting Enzyme by Peptides Hydrolysate Extracted from Walnut
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Bioactive peptides are defined as protein-based components having nutritional value and have proved roles important for the human health. In this study inhibition of angiotensin converting enzyme (ACE) by protein-based hydrolysate extracted from walnut (Juglanse regia. L.) seeds was evaluated. The peptide fraction obtained by enzymatic hydrolysis with trypsin showed higher ACE-inhibitory and lower IC50 value (0.39 ± 0.05 mg/mL) than obtained by hydrolysis with chymotrypsin and proteinase K. The study of kinetics showed that by increasing the concentration of the trypsin hydrolysate from 0.01–0.5 mg/mL, Km increased, while Vmax decreased. Also the value of Ki was found to be 0.17 ± 0.01 mg/mL, which means that binding affinity for the substrate decreased in the presence of inhibitor. The structural studies of ACE demonstrated that, in comparison with a commercial antihypertension drug (enalapril), the trypsin hydrolysate had no effect on secondary structure and less tertiary structure changes of protein was observed.
KeywordsWalnut Bioactive peptide ACE-inhibitory Kinetics Trypsin
Angiotensin converting enzyme
The support of University of Tehran, International Scientific Studies & Collaboration (CISSC)-Ministry of Science, Research and Technology in Iran, Center of Excellence in Biothermodynamics (CEBiotherm), Center of Excellence for Walnut Improvement and Technology of Iran, Iran National Science Foundation (INSF) and Iran National Elites Foundation (INEF) and UNESCO Chair on Interdisciplinary Research in Diabetes, Iran Society of Biophysical Chemistry is gratefully acknowledged. The authors also acknowledge the Headquarter of Science and Technology Development in Medicinal Plants of Iran’s Vice-President for Science and Technology Affairs.
Compliance with Ethical Standards
Conflict of interest
All author declares that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
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