Purification, Characterization, and Application for Preparation of Antioxidant Peptides of Extracellular Protease from Pseudoalteromonas sp. H2

Abstract

The study reported on the isolation of a metalloprotease named EH2 from Pseudoalteromonas sp. H2. EH2 maintained more than 80% activity over a wide pH range of 5–10, and the stability was also nearly independent of pH. Over 65% activity was detected at a wide temperature range of 20–70 °C. The high stability of the protease in the presence of different surfactants and oxidizing agents was also observed. Moreover, we also investigated the antioxidant activities of the hydrolysates generated from porcine and salmon skin collagen by EH2. The results showed that salmon skin collagen hydrolysates demonstrated higher DPPH (1,1-diphenyl-2-picrylhydrazyl) (42.88% ± 1.85) and hydroxyl radical (61.83% ± 3.05) scavenging activity than porcine skin collagen. For oxygen radical absorbance capacity, the hydrolysates from porcine skin collagen had higher efficiency (7.72 ± 0.13 μmol·TE/μmol). Even 1 nM mixed peptides could effectively reduce the levels of intracellular reactive oxygen species. The two types of substrates exerted the best antioxidant activity when hydrolyzed for 3 h. The hydrolysis time and type of substrate exerted important effects on the antioxidant properties of hydrolysates. The hydrolyzed peptides from meat collagens by proteases have good antioxidant activity, which may have implications for the potential application of marine proteases in the biocatalysis industry.

Potential Antioxidant Activity of Novel Antioxidant Peptides from Protein Hydrolysate of Peony Seed Dreg in Chemical and H2O2-Induced RAW264.7 Cells

“…After digestion, the enzyme was inactivated at 90 °C for 10 min. Te indene triketone colorimetric method was used to evaluate the free amino acid content at diferent treatment times [24]. Te hydrolysates were centrifuged at 12, 000 × g for 5 min.…”

Convergent evolution of the gut microbiome in marine carnivores

“…They have undergone significant habitat transitions during their evolution (Williams, 1999 ), and the order Cetacea has dramatically changed from herbivorous to carnivorous (Wang et al, 2016 ). Furthermore, the marine environment is a unique habitat, as its temperature is lower and salinity is higher than those of the terrestrial environment (Liu et al, 2019 ). Therefore, marine carnivores are ideal models for investigating convergent evolution (Uhen, 2007 ).…”