Background

Bee larvae are considered to be an important reservoir for proteins. However, little attention has been paid to the release of potential bioactive peptides from bee larva proteins. In this study the major protein in bee larvae was hydrolyzed in vitro by gastrointestinal enzymes. The peptide profile of the hydrolysis was characterized by gel filtration chromatography and tricine-SDS-PAGE. Furthermore, the bioactive peptide was isolated and identified by Q-TOF-MS/MS.

Results

The major bee larva protein was identified as apalbumin 2 and was more digestible into peptides with molecular weights lower than 3 kDa. The hydrolysate obtained after 3 h of digestion exhibited angiotensin I-converting enzyme (ACE)-inhibitory activity and was purified sequentially by gel filtration and RP-HPLC. The molecular weights of peptide fractions with ACE-inhibitory activity were distributed between 0.5 and 1.5 kDa. A novel peptide with highest ACE-inhibitory activity (IC50 54.9 μmol L?1) was purified by further RP-HPLC. The amino acid sequence of this peptide was identified as LLKPY (632.40 Da).

Conclusion
ACE-inhibitory peptides could be formed from bee larvae through gastrointestinal digestion. The most active peptide (LLKPY) is potentially useful as a therapeutic agent in treating hypertension.
This work has been published online on Journal of the Science of Food and Agriculture, Volume 95, Issue 5, pages 906–914, 30 March 2015.

More details are available on the link below: http://pubs.acs.org/doi/abs/10.1021/acs.jproteome.5b00625