Purification and identification of peptides with high angiotensin-I converting enzyme (ACE) inhibitory activity from honeybee pupae (Apis mellifera) hydrolysates with in silico gastrointestinal digestion

The objective was to identify peptides with ACE inhibitory activity generated from honeybee pupae hydrolysates. In addition, we simulated gastrointestinal digestion and predicted the potential cleavage sites of the identified peptides. Peptides derived from honeybee pupae were cleaved in silico by pepsin, trypsin, and chymotrypsin using the PeptideCutter tool of ExPASy. Honeybee pupae were hydrolyzed using four different proteases (Alcalase, neutrase, trypsin, and papain), and their ACE inhibitory activity and distribution of molecular weights were determined. The neutrase hydrolysates showed the highest ACE inhibitory activity. Then, the hydrolysates were isolated and purified using ultrafiltration, gel filtration chromatography, and reversed-phased high performance liquid chromatography. Three novel ACE inhibitory peptides were identified by LC–MS/MS, AVFPSIVGR, PPVLVFV, and PGKVHIT, which exhibited the most potent ACE inhibitory activity, with IC50 values of 6.64, 47.7859, and 223.869 µM, respectively. In simulated in silico gastrointestinal digestion, peptides AVPFSIVGR and PGKVHIT had the position of cleavage sites by pepsin, chymotrypsin and trypsin, and PPVLVFV was cleaved by pepsin and chymotrypsin. We hope these results support the application of honeybee pupa hydrolysates as functional ingredients in foods and pharmaceuticals.