Purification of Angiotensin-I-Converting Enzyme Inhibitory Peptides Derived from Camellia oleifera Abel Seed Meal Hydrolysate

Abstract

China is a large country that produces Camellia oleifera Abel seed meal (COASM), a by-product of tea-seed oil, which is only used as an organic fertilizer, resulting in a serious waste of high-quality resources. The preparation of the ACE inhibitory peptide from COASM and the study of its functional properties are of practical importance in improving the comprehensive utilization of COASM. Our manuscript presents an optimized preparation of ACE inhibitory peptides with alkaline protease and enzyme kinetics parameters. Ultrafiltration, gel chromatography, and RP-HPLC purification were conducted for ACE inhibitory peptides, and peptide molecular weight distribution and amino acid composition were analyzed in the enzymolysis liquid. The following were the conditions of the optimized enzymatic hydrolysis to obtain ACE inhibitory peptides from COASM: 15 times of hydrolysis in distilled water for 3.5 h at 50°C, pH = 8.5, substrate concentration of 17 mg/g, and addition of 6% (w/w) alkaline protease. Under this condition, the peptides produced exhibited an ACE inhibition rate of 79.24%, and the reaction kinetics parameters are as follows: Km = 0.152 mg/mL and Vmax = 0.130 mg/mL·min. The majority of ACE inhibitory peptides from COASM have molecular weight below 1 kDa, and a high ACE inhibitory rate was achieved after dextran gel chromatography separation and purification (whose IC50 was 0.678 mg/mL). The hydrophobic amino acid content in this fraction reached 51.21%.

Bioactive Peptides from Velvet Bean Tempe: Neutrase-Catalyzed Production in Membrane Reactor

“…A significant increase in ACEi activity (i.e., low IC50) was observed by employing lower MWCOs to the permeate produced under optimum conditions (Figure 6). This trend has also been reported in various studies (Herrera Chalé et al, 2014;Tuz and Campos, 2017;Yao et al, 2019;Sitanggang et al, 2021b;Kurniadi et al, 2023;Sitanggang et al, 2023). The strongest ACEi activity was found in the lowest fraction (<2 kDa), measuring 0.23 µg protein/mL.…”

Simultaneous extraction of protein and oil from green coffee beans

“…Considering the amount of proteins for the skims (Table 5.2) and degree of hydrolysis (DH) did not present significative differences (p>0.05) when using the same protease (except for (C+H) + NP that presented higher DH) (Souza Almeida et al, 2021), the increase in ACE inhibition probably is not associated with further proteolysis, but instead, it could be associated with protein structural modification over time. This result agrees with the observed results for Camellia oleifera Abel seed meal (COASM), where authors demonstrated that the degree of hydrolysis was not positively correlated with the ACE inhibition rate (Yao et al, 2019). Therefore, the differences found may be associated with protein structural modification or type of phenolics released during the extractions, reinforcing the activity of both peptides and phenolics present in the coffee extracts.…”

Discovery of a Multifunctional Octapeptide from Lingzhi with Antioxidant and Tyrosinase Inhibitory Activity

“…The mass deviation of the synthesized peptide was 0.0396%. With an 89% purity, this indicates that the identity of the synthetic peptide was acceptable to be used for further biochemical assays such as antioxidant assays, enzyme kinetic reactions, and semi-quantitative applications [14].…”