Lourdes Ramirez Fuentes | ALES Graduate Seminar

Date(s) - 27/04/2021
9:00 am - 10:00 am

A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Lourdes Ramirez Fuentes. This seminar is open to the general public to attend.

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Meeting ID: 971 1940 7386
Passcode: 069169

Thesis Topic: Development and characterization of peptides with antidiabetic activities from oat protein

MSc with Dr. Lingyun Chen

Seminar Abstract:

Type 2 diabetes mellitus (T2DM) occurs when the cells in the body are unable to respond to the effect of insulin, resulting in a state of hyperglycemia that could involve other health complications. The prevalence of this disease generates a great concern worldwide and suggests a move towards prevention through diet and lifestyle modifications. For instance, oats consumption has been related to blood lipid and glucose regulation, mostly from its fiber and phenolic compounds. Recently, oat protein content started gaining importance due to its functional capacities and glucose regulatory effects; however, research is still limited. Exploring oat protein health benefits could leverage the Canadian oat production process to obtain value-added products since western provinces are known to be the major oat producers in the country. Therefore, this research aimed to generate antidiabetic peptides from oat protein to inhibit α-amylase, α-glucosidase, and dipeptidyl peptidase (DPP)-IV enzymes.

In this study, oat protein hydrolysates were prepared by alcalase and flavourzyme treatment and then fractionated based on different molecular weights and hydrophobicity. Enzyme inhibition assays in vitro indicated that the relatively hydrophobic fraction with a molecular weight of 1-5 kDa inhibited enzymes that regulate glucose digestion, absorption, and metabolism activities. Identification of oat peptides from the most effective sequence was done using LC-MS/MS. The analysis disclosed the presence of two eight amino acid sequences from the most effective fractions, identified from 12S oat globulin (Gly-Asp-Val-Val-Ala-Leu-Pro-Ala and Asp-Val-Val-Ala-Leu-Pro-Ala-Gly) and new de novo sequences rich in amino acids like proline, leucine, valine, phenylalanine, and glutamine. The results suggest that the presence of these amino acids at specific locations within the peptide chain play a crucial inhibitory role and may favor hydrophobic interactions and hydrogen bonding at the enzymes’ active or allosteric sites. Hydrophobic characteristics combined with the presence of amino acids like proline, valine, and leucine, especially the enclosed Leu-Pro sequence found in potent DPP-IV inhibitors, might have conferred their antidiabetic effect. α-Amylase, α-glucosidase, and DPP4 enzymes are used as targets in the development of antidiabetic drugs. Thus, the ability to generate peptides with antidiabetic activities from oat represents a strategy to develop natural healthy products or functional foods for T2DM prevention and management.