Purification and Identification of Antioxidant Alcalase-Derived Peptides from Sheep Plasma Proteins

Abstract

In this study, sheep plasma was submitted to Alcalase-hydrolysis and peptides with better antioxidant properties measured through both the ferric-reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability assays were isolated and identified. After hydrolysate ultrafiltration and semi-preparative reverse-phase high-performance liquid chromatography, nine fractions (F1–F9) were obtained, with the two first (F1 and F2) showing the greatest antioxidant potential. These two fractions were further separated by the AKTA purifier system to generate four (F1-1–F1-4) and five (F2-1–F2-5) fractions, respectively, with two of them (F1-2 and F2-1) exhibiting appreciable FRAP activity and DPPH radical scavenging ability. Using liquid chromatography-tandem mass spectrometry, three antioxidant peptides were identified. From their amino acid sequences (QTALVELLK, SLHTLFGDELCK, and MPCTEDYLSLILNR), which include amino acids that have been previously reported as key contributors to the peptide antioxidant properties, it can be maintained that they come mainly from serum albumin. These results suggested that the sheep plasma protein can be considered as a good source of antioxidant peptides and bring forth new possibilities for the utilization of animal blood by-products.

Use of Alcalase in the production of bioactive peptides: A review

“…The hydrolysates showed strong 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity [355]. In another paper, a sheep plasma hydrolysate was produced by Alcalase-hydrolysis [356]. Peptides with high antioxidant properties measured through both the ferric-reducing antioxidant power and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability were isolated from this hydrolysate [356].…”

Identification and Characterization of Novel Antioxidant Protein Hydrolysates from Kiwicha (Amaranthus caudatus L.)

“…In this sense, the smaller size of kiwicha peptides may be attributed to faster hydrolysis with Bioprotease compared to Alcalase. While Bioprotease increased HD up to 20% after 5 min, 10–15 min of hydrolysis with Alcalase are used to reach 20% HD [ 48 ].…”

“…Immune response and the control of oxidative stress are two interconnected processes implicated in the maintenance of homeostasis [ 48 ]. Inflammation is an important normal immune response during lesions and infections.…”

“…In this sense, the smaller size of kiwicha may be attributed to faster hydrolysis with Bioprotease compared to Alcalase. W protease increased HD up to 20% after 5 min, 10-15 min of hydrolysis with Alc used to reach 20% HD [48]. The average molecular weight of hydrolysates is a leading factor that determines their biological properties.…”

Identification of Potential Peptide Inhibitors of ACE-2 Target of SARS-CoV-2 from Buckwheat & Quinoa

“…Food protein-derived bioactive peptides have been reported to possess antioxidant (Hou et al 2019 ), immunomodulatory (Chalamaiah et al 2018 ), antihypertensive (Bhat et al 2017 ), anti-inflammatory (Meram and Wu 2017 ), anti-microbial (Mohanty et al 2016 ), hypocholesterolaemic (Nagaoka 2019 ), anti-diabetic (Admassu et al 2018 ), anti-cancer properties (Díaz-Gómez et al 2017 ), among various others. Hence, there is considerable interest in development of peptides for commercial use as additives or functional food products/nutraceuticals, which can improve human health for specific or generic use (Chalamaiah et al 2019 ).…”