Study On Properties Of Angiotensin Converting Enzyme And Effect Of Its Activity Inhibited By Collagen Peptides

As a chronic disease,Hypertension threats human health all over the world and it have shown a rising trend in incidence rates every year.High blood pressure can affect the body organs such as the heart,brain and kidney,leading to various health-related diseases,and it is also one of the main incentives which lead to cardiovascular disease.At the same time,it threats animal health considerably as well.Today,pet animals such as dogs and cats play more and more important roles in people’s lives.It is easier to suffer from hypertension for them now as for pampered and exercise lacked.Nowadays,people take animal walfare more seriously which lead how to make safe and effective treatment for animal hypertension to become a great concern in the whole society.It has been reported that Angiotensin Converting Enzyme(ACE)associated with human and animal blood pressure,which is a drug target for treatment of hypertension disease.Therefore in-depth study of ACE is not only a positive effect on prevention and treatment of hypertension,but also very helpful to new ACEI’s manufacture and development.Collagen,as a beauty health product,has been reported for its ACE inhibition in recent years.Three different collagens were added in the reaction in order to evaluate and compare their ACE inhibition in this work with a view to provide the worthful data for exploring collagens with ACE inhibitory activity and treatment of hypertension for humans and animals.As the material,fresh lung was homoganated and centrifuged,then isolated and purified of ACE by utilizing isoelectric point of the protein and ammonium sulfate fractionation to obtain a crude enzyme solution.After reacting with the substrate Hip-His-Leu(HHL)to generate Hippuric Acid(HA),the activity of ACE was examined by using spectrophotometry.From the results of electrophoresis we could know that although ACE existed in the lung supernatant which had been homoganated and centrifugated,but there were also a number of hybrid proteins with high concentration in it.By utilizing isoelectric point of the protein and ammonium sulfate fractionation,hybrid proteins can be removed effectively which made the concentration and purity of ACE higher.Spectrophotometric assay was used to measure the activity of ACE which equaled to 19.83×10-3U per microgram protein.After extracting ACE from the lung,the study of its enzymatic properties could be carried out.The results showed that:ACE was actived at moderate temperatures,the optimum temperature was 40℃.and it was better for ACE to active in a slightly alkaline environment,the optimum pH was 8.0;350mmol/L chlorine ions enhanced the activity of ACE to a large extent;EDTA inhibited the activity of ACE at low concentrations;as to metal ions,Co2+played a great role in enhancing the activity of ACE,Zn2+had little effect on activity of ACE,Mg2+and Fe2+inhibited the activity of ACE in different degrees.It was found that collagens had effective inhibition on the activity of ACE by adding them in the reaction.After compared,the ACE inhibitory activity of China-made collagen which was extracted at low temperature was significant higher than the other two commercial collagens.So the ACE inhibitory effect of collagen could be further improved by appropriate extraction method.