Research On Preparation Of Low Molecular Weight Corn Peptides And Its Effect On ADH And ACE Enzyme Activity

Alcohol dehydrogenase (ADH) is the Oxidoreductase of alcohol, and plays an important role in alcohol metabolism. ADH exists primarily on the liver, and ADH catalyzes alcohol into acetaldehyde. When alcohol is absorbed through the gastrointestinal tract, only 2%-10% alcohols are excreted through the kidney and lung and 90%-98% alcohols in the liver metabolism. Alcohol metabolism in the human body mainly through the following method to accomplish: ADH method MEOS method, CAT method. ADH which exists primarily in the liver, ADH plays an important role in alcohol metabolism; acetaldehyde is oxidated into acetic acid by ALDH. Acetic acid come into TCA cycle and goes out from body. ADH activity in the body can affect the metabolism of alcohol, if the enzyme activity inhibited, the body can absorb more alcohol and alcohol will harm the body.ACE is a glycoprotein and contains Zn2+ and Cl-. ACE widely exists in human tissues and plasma. ACE is multifunctional enzyme and ACE plays an important role in the RAS system and KKS system in the regulation of blood pressure.RAS system is an important regulator of blood pressure endocrine system and renin enzyme is a protein decomposition enzyme in this system. Renin can make angiotensin release AngⅠ, and AngⅠis the substrate of ACE. ACE hydrolysis His-Leu generated AngⅡ, and AngⅡis the most important bio-active ingredients in RAS system. AngⅡis the strongest substances to make blood vessel contract, which can make the blood vessel smooth and muscle contraction and rapidly induce pressor effects. KKS system is the endogenous depressurization system in the human body. Kallikrein act on Kininogenase, and generate bradykinin which can make blood vessel relax. ACE in the KKS system can make bradykinin inactivation. The KKS system in the inhibition lead to blood vessel contract and blood pressure step up.RAS and KKS in blood pressure regulation is a system of mutual antagonism, and the maintenance of its balance plays an important role in normal blood pressure. Its imbalance is one of the important factors of Hypertension. because ACE in the RAS and the KKS system plays an important role in regulating blood pressure, ACE inhibition activity on the lower blood pressure have a positive effect.Corn peptides (CP) is a kind of bioactive peptides prepared form corn gluten meal (CGM). First, we prepared the zein form CGM using ethanol precipitation. Then the zein is hydrolyzed by a type of alkaline protease, which has a wide substrate specificity, at 50℃and pH 8.0. The degree of hydrolysis(DH) was controlled to be 25%. After via a series of separation using molecular sieve, the Hydrolysate were freeze-dried and the CP was obtained.Bioactive peptides prepared from the plant protein in vitro and in vivo can be effective in raising ADH activity. In vitro, corn separation and purification of peptides C2 in the high concentration have high capacity of promotion ADH than that of GSH. In vivo, after mice drink alcohol 1 h,1.5h,2h, low-dose,normal dose and high dose of corn peptide increased ADH activity in mouse liver. Corn peptide is also ACE inhibitors, when corn peptide concentration is 20mg/l, and corn peptide on the ACE inhibition rate is higher than 40%. With the increase of corn peptide the concentration of ACE inhibition rate is gradually increasing. When corn peptide concentration is 100mg/ml, the ACE inhibition rate of more is more than 80%. From the article, we can see that the corn peptide and its separation and purification products can inhibit the activity of ACE and have a lower blood pressure.On the basis of above content, we not only produced a broad application of the corn peptide, but also confirmed corn peptide can promote alcohol metabolism and the role of anti-hypertension. We will provide theoretical foundation and experimental basis for the further development and application of corn peptides.