Purification and Identification of Cholesterol Micelle Formation Inhibitory Peptides of Hydrolysate from High Hydrostatic Pressure-Assisted Protease Hydrolysis of Fermented Seabass Byproduct

Abstract

This research focuses on the proteolytic capacity of sea bass byproduct (SB) and their hypocholesterolemic activity via the cholesterol micelle formation (CMF) inhibition. SB was fermented with seven mixed lactic acid bacteria for 5 h at 42 °C. The lactic fermented SB was hydrolyzed with Protease N for 6 h under HHP to obtain the SB hydrolysates (HHP-assisted Protease N hydrolysis after fermentation, F-HHP-PN6). The supernatant was separated from the SB hydrolysate and freeze-dried. As the hydrolysis time extended to 6 h, soluble protein content increased from 187.1 to 565.8 mg/g, and peptide content increased from 112.8 to 421.9 mg/g, while inhibition of CMF increased from 75.0% to 88.4%. Decreasing the CMF inhibitory activity from 88.4% to 42.1% by simulated gastrointestinal digestion (FHHP-PN6 was further hydrolyzed by gastrointestinal enzymes, F-HHP-PN6-PP) reduced the CMF inhibitory activity of F-HHP-PN6. Using gel filtration chromatography, the F-HHP-PN6-PP was fractioned into six fractions. The molecular weight of the fifth fraction from F-HHP-PN6-PP was between 340 and 290 Da, and the highest inhibitory efficiency ratio (IER) on CMF was 238.9%/mg/mL. Further purification and identification of new peptides with CMF inhibitory activity presented the peptide sequences in Ser-Ala-Gln, Pro-Trp, and Val-Gly-Gly-Thr; the IERs were 361.7, 3230.0, and 302.9%/mg/mL, respectively.

Biomolecules under Pressure: Phase Diagrams, Volume Changes, and High Pressure Spectroscopic Techniques

“…Several simple model systems were studied and characterized up to now, and volumetric aspects of simple and quite complex systems have been revealed [ 10 , 11 , 12 , 13 , 14 ]. Parallel to these discoveries of basic science, practical applications were invented too, mainly in the field of food science [ 5 , 15 , 16 ]. High-pressure food processing has become a reality, and high-pressure processed food is available now—not only for high pressure conference participants, but also in the shops as well.…”

Fermented milks with specific Lactobacillus spp. with potential cardioprotective effects

“…Interestingly, Lin et al ( 2010 ) reported that peptidic digestion significantly decreased (0.7 times) inhibition of micellar solubility of cholesterol and was attributed to the generation of new specific peptides. Additionally, Chen et al ( 2021 ) observed a decrease of inhibition of micellar solubility of cholesterol from 88.4 to 42.1%. Hence, the importance of determining the stability of potential bioactive peptides after simulated gastrointestinal digestion.…”

“…On the other hand, other peptide food sources have also shown inhibition of micellar solubility of cholesterol, such as soybean (81.3%) (Zhong et al 2007 ), freshwater clam meat (18.5%) (Lin et al 2010 , 2017 ), chickpea (50%) (Yust et al 2012 ) and fermented sea bass byproduct (42.1%) (Chen et al 2021 ); among others. Interestingly, Lin et al ( 2010 ) reported that peptidic digestion significantly decreased (0.7 times) inhibition of micellar solubility of cholesterol and was attributed to the generation of new specific peptides.…”

Novel Plant-Protein (Quinoa) Derived Bioactive Peptides with Potential Anti-Hypercholesterolemic Activities: Identification, Characterization and Molecular Docking of Bioactive Peptides

“…A possible explanation could be that the cleavage sites that the enzyme binds to was not fully exposed, which consequently reduced the inhibition effect. However, the protease hydrolyzed under hydrostatic pressure processing showed an increased inhibition rate of up to 49.1% [ 30 ].…”

“…A previous study reported the major role the hydrophobicity of peptides plays in the anti-hypercholesterolemic activity of peptides, which is mainly the binding of bile acids. Identified peptides with anti-hypercholesterolemic ability inhibit bile acids absorption in the ileum; as a result, they reduce the level of blood cholesterol concentration [ 30 ]. Hydrophobic amino acids, namely alanine, leucine, phenylalanine, proline, etc.…”