title: Structural and antioxidant modification of wheat peptides modified by the heat and lipid peroxidation product malondialdehyde.
abstract: Wheat peptides, the biological active peptides derived from foods, has an array of biological actions, including antiobesity, antimicrobial, and angiotensin I-converting enzyme inhibitory effects in mammalian species. Recent studies showed that some wheat peptides may show the noteworthy antioxidant potency against the peroxidation of lipids or fatty acids, but the effect of oxidation on its antioxidant activities is unclear. In the present study, we demonstrate that heat and malandialdehyde (MDA)-oxidized wheat peptides lose its surface hydrophobicity and reducing power, and show a relatively lower free radical-scavenging activitiy in vitro. Those modifications also lead to gradual formation of aggregates in wheat peptides and induce more reactive oxygen species (ROS) production in vivo. These findings indicate that oxidation may influence the functional properties and directly alter the structure of wheat peptides, and lead to the loss of its antioxidant potency both in vitro and in vivo, thereby providing a novel explanation for some of the potential health risks proposed for oxidized food in human.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, P R China.
authors.forename: Xue
authors.initials: X
authors.lastname: Tang
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Wu
authors.forename: Guowei
authors.initials: G
authors.lastname: Le
authors.forename: Jiao
authors.initials: J
authors.lastname: Wang
authors.forename: Kaijian
authors.initials: K
authors.lastname: Yin
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Shi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry; D006358:Hot Temperature / Q000009:adverse effects; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000737:chemistry*; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000009:adverse effects / Q000737:chemistry*; D011487:Protein Conformation; D011897:Random Allocation; D017382:Reactive Oxygen Species / Q000097:blood; D019163:Reducing Agents / Q000009:adverse effects / Q000737:chemistry; D055314:Seed Storage Proteins / Q000009:adverse effects / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013499:Surface Properties; D014908:Triticum / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; D019163:Reducing Agents; D055314:Seed Storage Proteins; D008315:Malondialdehyde