Study On The Technology Of Enzymatic Production Of ACE Inhibitory Peptides From Wheat Gluten

Angiotensin converting enzyme(ACE) plays an important physiological role in regulating blood pressure.Currently,many ACE inhibitors(ACEI) have been used as antihypertensive agents.As the peptide of ACEI deriving from the food source was high safety and no side effects on prevention and cure high blood pressure,ACEI peptide has become a hot spot in the domain of HBP research and development.In the present study,the ACEI peptides were prepared from wheat gluten protein with protease hydrolysis,and the high inhibitory hydrolysis product were refined from the crude hydrolysate,by a series of separating way.The main research contents were as follow.Angiotensin converting enzyme(ACE) was extracted by differential centrifugation,the solubilization of sodium deoxycholate and the means of saturation ammonium sulfate fraction precipitation.The ACE acitivity was 2.5U/mg,and after two months it could kept steady.Taking ACE inhibitory acivity as index,after screening of severl commercial proteases, alcalase was used to hydrolysis as indexes,the experiment of Response Surface Analysis (RSA) was carried out by the program of Statistical Analysis System(SAS).design was used to optimize the hydrolysis conditions of whey protein with alcalase.Ultrafiltration was applied to isolated ACE inhibitory peptides by membrance of which molecular cut off was 12 kDa,5 kDa,3kDa.After ultrafiltration most of the peptide which molecular weight(MW) were more than 3000Da were removed and the ACE inhibitory activities of the permeates separately increased 73.4%.Then most of the salt and amino acids,etc.were removed through nanofiltration,The acitivity of the remain increased 74.9%.The hydrolysate of wheat gluten was isolated by CM-cellulose ion exchange chromatography(IEC) and ACE inhibitory activities IC₅₀ were 0.066mg/mL.And the production was further purified by reversed-phase HPLC,then the peptides with high ACE inhibitory activity were obtained.To study the effects of inhibitory peptides of Wheat gluten protein on Spontaneously hypertensive rats(SHR).The Spontaneously hypertensive rats(SHR) were each given 2mL/100g bw inhibitory peptides of Wheat gluten protein,by single gastric intubation the systolicblood pressure of rats was decreased significantly.This result testified that the inhibitory peptides of Wheat gluten protein had apparent effect on depressingblood pressure.