Purification and identification of angiotensin I-converting enzyme-inhibitory peptides from apalbumin 2 during simulated gastrointestinal digestion.
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).


CONCLUSIONS
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.
Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China; National Research Centre of Bee Product Processing, Bee Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100093, China.
Xiang
X
Xu
Yanxiang
Y
Gao
D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D056630:Beekeeping / Q000191:economics; D001516:Bees / Q000737:chemistry; D002681:China; D002918:Chymotrypsin / Q000378:metabolism; D004063:Digestion; D055808:Drug Discovery; D019476:Insect Proteins / Q000737:chemistry / Q000191:economics / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D007814:Larva / Q000737:chemistry; D008954:Models, Biological; D008970:Molecular Weight; D009842:Oligopeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D011492:Protein Hydrolysates / Q000737:chemistry / Q000191:economics / Q000378:metabolism / Q000494:pharmacology; D059748:Proteolysis; D014357:Trypsin / Q000378:metabolism; D014866:Waste Products / Q000032:analysis / Q000191:economics
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D019476:Insect Proteins; D009842:Oligopeptides; D010446:Peptide Fragments; D011492:Protein Hydrolysates; D014866:Waste Products; C000603306:leucyl-leucyl-lysyl-prolyl-tyrosine; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; D014357:Trypsin
ACE-inhibitory peptides; apalbumin 2; bee larvae; gastrointestinal digestion