Screening And Activity Study Of Angiotensin-converting Enzyme And Dipeptidyl Peptidase-IV Inhibitory Peptides In Beer

Hypertension and diabetes are two of the main risk factors for atherosclerosis and cardiovascular disease development,and both diseases frequently occur together.The commonly used antihypertensive drugs and hypoglycemic drugs in clinic will make certain side effects.Food-derived polypeptide was a kind of polypeptide with great development potential,which has the functions of preventing and treating diseases and regulating human physiological functions.These functions are not possessed by the original protein and its constituent amino acids.Beer is the oldest beverage of human beings,which contains a variety of nutrients,high protein content and low energy.The protein in beer can be degraded into more soluble peptides and transferred to the final product.Polypeptides had smaller molecular weight than proteins and were more easily absorbed and utilized by human body.In this paper,Tsingtao white beer,dark beer and draft beer were used as the research objects to extract,identify,screen and verify the activity of beer peptides.The small molecular peptides with high ACE and DPP-? inhibition were obtained.The main results are as follows:1.Tsingtao white beer,dark beer and draft beer were used as raw materials,the crude peptide extracts were studied.The peptides were qualitatively analyzed by UHPLC-Q-Oritrip-MS~2,and the peptides with a confidence of more than 85%were selected.Among them,68 peptides were identified in white beer,41 in black beer and 50 in draft beer.From the total ion flow diagram,it can be seen that there were some similarities and significant differences in the peak time of three kinds of beer peptide extracts.There were 16 overlapping peptides between white beer and draft beer,14 overlapping peptides between white beer and black beer,and 13overlapping peptides between black beer and draft beer.There are 8 peptides in three kinds of beer.The similarity of peptides may be due to the similarity of brewing materials.Principal component analysis was used to analyze the peptides of three kinds of beer.It was found that there were significant differences among three different brewing methods.2.Based on the identified peptides,the peptides with high ACE inhibition and DPP-? inhibition were screened.First,the Peptide Ranker was used to evaluate its activity and set a threshold value of 0.5 to screen out the peptides with high biological activity.At the same time,according to the previous studies on the amino acid active sites of inhibitory peptides,the peptides that conform to the amino acid sequence of ACE and DPP-? inhibitory peptides were screened out.Finally,the molecular docking simulation score of these peptides was evaluated.Six peptides were finally selected,including two peptides LAKLQR and VPFPHTP in white beer,two peptides DLGGFFGFQR and LPQQQAQFK in black beer,two peptides LNFDPNR and LAQMEAIR in draft beer.3.The ACE and DPP-? inhibitory activities of the selected peptides were verified by in vitro activity experiments,and then the structure-activity relationship between the peptides and ACE and DPP-? was explored by molecular docking.The results showed that all the six peptides had certain ACE and DPP-? inhibitory activity,and the activity increased with the increase of peptide concentration,showing a dose-response relationship.The results of molecular docking showed that all the six peptides could interact with ACE and DPP-? enzymes through hydrogen bonding and hydrophobic interaction,and confirmed that the interaction mode between the six peptides and protease was noncompetitive inhibition.