Identification of novel antioxidant peptides from snakehead (Channa argus) soup generated during gastrointestinal digestion and insights into the anti-oxidation mechanisms

Abstract

Antioxidant peptides obtained from snakehead (Channa argus) soup (SHS) after simulated gastrointestinal (GI) digestion were separated, identified and characterized. Results showed that the fraction with MW < 3 kDa had the highest antioxidant capacity. Four novel antioxidant peptides were identified after RP-HPLC and UPLC-MS/MS. PGMLGGSPPGLLGGSPP and SDGSNIHFPN had the highest DPPH radical scavenging activity (IC50 = 1.39 mM) and Fe 2+ chelating ability (IC50 = 4.60 mM), respectively. Structures in silico for IVLPDEGK, PGMLGGSPPGLLGGSPP and SDGSNIHFPN suggest that at least one β-turn and/or α-helix, are associated with antioxidant activity. Moreover, our results showed that these three peptides docked with a recombinant Kelch-like ECH-associated protein 1 (Keap1) with a binding score greater than TX6, a good ligand of Keap1. The cell viability assay also showed significant cytoprotective effects against H2O2-induced cellular oxidative damage. This information implies that antioxidant mechanisms of novel peptides occurred via activation of cellular anti-oxidation Keap1-Nrf2 signaling pathway.

Purification and characterization of a novel angiotensin I‐converting enzyme‐inhibitory peptide derived from Alaska pollack skins

“…The low ACE inhibitory activity may partially be explained that it has less relatively large molecular weight and a longer molecular chain. Because low MW and short peptides are more active when reacting with free radicals as electron donors, they are more stable and can stop chain reaction (Zhang et al., 2020).…”

“…(2018) and Zhang et al. (2020) with some modifications. The crystal structure of ACE (Human, PDB: 1O8A) was downloaded from Protein Data Bank (http://www.rcsb.org/structure/1O8A).…”

Purification and Identification of Novel Xanthine Oxidase Inhibitory Peptides Derived from Round Scad (Decapterus maruadsi) Protein Hydrolysates

“…The molecular weight (MW) distribution of RSHs was determined by using LC-20AD high-performance liquid chromatography (HPLC) system (Shimadzu Co., Tokyo, Japan) with a TSK-Gel G2000SWXL column (300 × 7.8 mm, 5 µm) according to the method of Zhang et al (2021) [40] with slight modifications. RSHs (2 mg/mL) were prepared with ultrapure water.…”

Roles of Dietary Bioactive Peptides in Redox Balance and Metabolic Disorders

“…Recently, numerous novel antioxidant peptides that stimulate the Keap1 - Nrf2 -ARE antioxidant signaling pathway and antioxidant enzymes have been isolated from different dietary sources such as casein [ 40 ], milk protein concentrate [ 41 ], corn gluten [ 31 ], soybean [ 42 ], walnut [ 43 ], potato, Moringa oleifera seeds [ 25 ], watermelon seeds [ 39 ], Crassostrea rivularis [ 44 ], krill [ 38 ], turtle [ 45 ], Mytilus coruscus [ 46 ], Channa argus [ 3 ], and silver carp muscle [ 12 ]. Snakehead ( Channa argus ) soup was hydrolyzed using pepsin and pancreatin and identified four antioxidant peptides, IVLPDEGK, PGMLGGSPPGLLGGSPP, SDGSNIHFPN, and SVSIRADGGEGEVTVFT [ 3 ]. The authors performed molecular docking studies for the peptides and indicated that peptides could bind to the active site of Keap1 and thereby activate the cellular antioxidant Keap1-Nrf2 signaling pathway.…”

“…The BP sequences present in the food proteins are generally hidden in the inner core of the parent proteins [1]. However, bioactive peptides can be released from food proteins with the help of several techniques including proteolysis, microbial fermentation, and gastrointestinal (GI) digestion [2][3][4]. Among these methods, in vitro enzymatic hydrolysis using commercial proteolytic enzymes is the widely employed method in recent times.…”