Screening of angiotensin I-converting enzyme inhibitory peptides from rapeseed by bioinformatics, QSAR and molecular docking

The purpose of this study was to screen ACE inhibitory peptides with high activity from rapeseed protein hydrolyzate.Firstly a peptide library was established through in-silico hydrolysis on rapeseed protein, and the IC50 values were predicted by the QSAR model. Then six target peptides were found with the combined use of NANO-Q-TOF mass spectrometry. Finally the target peptides were hydrated molecular docked with the Zn2 +active sites of ACE.The results indicated that the peptides GRD, with a predicted IC50 of 7.54μmol /L, showed high ACE inhibitory activity, and it was a new unreported ACE inhibitory peptide which formed competitive inhibition of the Zn2 +active center on ACE. Sequence alignment showed the source protein of GRD was a Napin protein ( oleosin-like protein, NCBI in ID: ABD14345) , and the Pepsin cleavage sites for GRD was ABD14345/50.