Grant: Discovery Grants Program - Individual

The link between foods and health is well known meanwhile, the nature of compounds in foods that are beneficial, and their mechanisms are still mostly undefined. Proteins for example provide blocks (i.e. amino acids) to the body to build its own proteins. In processed foods, protein properties such as gelation, emulsion or foam stabilization, and water-holding capacity are important for optimum formation. These functions of proteins are however dependent on their purity, and their polypeptide composition which must be determined through scientific research. In cereals, benefits are often attributed to soluble fibres and polyphenols, meanwhile, benefits associated with their proteins and peptides are gradually being discovered. Peptides produced from the hydrolysis of proteins have for example antioxidant activity in food systems and some can be absorbed and provide biological functions including lowering blood pressure or reducing inflammation. There are still many challenges in obtaining high-purity proteins from plant foods as well as determining optimum conditions to release bioactive peptides. Additionally, standardization requires the identification of peptides that can serve as markers either in a food or in the biological environment. This proposed application is to fill gaps related to the purification of proteins from cereal brans like those from oats, to discover new peptides that can inhibit enzymes involved in nutrients absorption and metabolisms, and to determine the mechanism of action. One of the enzymes will be protein tyrosine phosphatase-1B (PTP1B) whose inhibition is expected to slow the dephosphorylation of insulin receptor, increase glucose uptake in cells, and enhance the secretion of glucagon-like peptide-1. The determination of the effects of food bioactive peptides to inhibit the activity of PTP1B is new and this will be achieved using colon cell lines. How TPP1B inhibition affects the secretion of glucagon-like peptide-1, a hormone that stimulates nutrient uptake by cells is also new. The proposed research work will generate knowledge on the absorption, transport and metabolism of unique peptides derived from cereals proteins at a cellular level. In addition, a model to predict the activity of peptides or elucidate their mechanisms will be developed using molecular dynamics. The identified peptides will have applications in the formulation of novel foods to maintain health and manage chronic diseases.