Discovery and Study of Novel Antihypertensive Peptides Derived from Cassia obtusifolia Seeds

Abstract

Antihypertensive peptides were screened from thermolysin hydrolysate of Cassia obtusifolia seeds (Jue Ming Zi) using two independent bioassay-guided fractionations, reversed-phase high-performance liquid chromatography (RP-HPLC), and strong cation-exchange (SCX) liquid chromatography coupled with angiotensin I-converting enzyme (ACE) inhibitory assay. The identical peptide in the most active RP-HPLC and SCX fractions was simultaneously de novo sequenced as FHAPWK with high-resolution mass spectrometry. FHAPWK (IC 50 = 16.83 ± 0.90 μM) was further identified as a competitive inhibitor and a true inhibitor on ACE by a Lineweaver−Burk plot and preincubation experiment, respectively. The molecular docking simulation indicated that FHAPWK could interact with several key residues of the ACE active site, which is consistent with the result of the inhibitory kinetics study. Moreover, its antihypertensive effect was demonstrated using the animal model of spontaneously hypertensive rats. It is concluded that FHAPWK is the first reported antihypertensive peptide derived from thermolysin hydrolysate of C. obtusifolia seeds.

Characterization of Novel Dipeptidyl Peptidase-IV Inhibitory Peptides from Soft-Shelled Turtle Yolk Hydrolysate Using Orthogonal Bioassay-Guided Fractionations Coupled with In Vitro and In Silico Study

“…Therefore, a vital step in studying bioactive peptides is to know how to make them more efficiently accessible, thereby reducing researching time and finances to screen and eliminate inferior peptides. According to the different characters of each peptide such as the molecular weight, hydrophobicity, and other physicochemical properties, several orthogonal bioassay-guided methods were applied individually as well as the combination of two or three chromatography techniques which were utilized [ 4 , 26 , 27 , 28 , 29 ]. To fractionate SSTY GI hydrolysates, two column chromatography methods (RP and SCX) with different separation mechanisms were performed in parallel.…”

“…Potential peptides were synthesized based on the method reported by Shih et al, [ 28 ] with slight modification. Identified peptide sequences were synthesized starting from C-terminal to the end of N-terminal using Wang resins as the solid support based on the CEM Discover reactor (CEM Microwave Technology Ltd., Buckingham, UK).…”

Characteristics of Food Protein-Derived Antidiabetic Bioactive Peptides: A Literature Update

“…Moreover, MRM can provide an analysis of multiple peptides in a single LC-MS run. Several studies reported on the application of the MRM method to measure the peptide amount present in food proteins like egg and plants [98,[136][137][138][139].…”

ACE Inhibitory Activity and Molecular Docking of Gac Seed Protein Hydrolysate Purified by HILIC and RP-HPLC

“…To the best of our knowledge, this study is the first report that introduces novel ACE inhibitory peptides from GSPs hydrolysate. Compared to other peptides derived from other food-sourced proteins reported previously, ALVY (IC 50 = 7.03 ± 0.09 µM) showed a remarkable ACE inhibitory activity superior than those generated from other plant seeds, such as Cassia obtusifolia seeds (FHAPWK, IC 50 = 16.8 μM) [ 38 ], barley (FQLPKF, GFPTLKIF, NFLARF, and ALRYFM IC 50 values ranged from 28.2 to 200 μM) [ 39 ], bitter melon seeds (VSGAGRY, IC 50 = 8.6 μM) [ 40 ], hemp seeds (WVYY, WYT, SVYT, and IPAGV, IC 50 values ranged from 27 to 574 μM) [ 41 ], and wheat germ (QV, NPPSV, and VEW, IC 50 values ranged from 26.8 to 115.2 μM) [ 42 ].…”