Isolation, partial purification and characterization of angiotensin converting enzyme from rat (Rattus norvegicus) lungs

M.A. Abdulazeez, B.G. Kurfi
2017 Bayero Journal of Pure and Applied Sciences  
Angiotensin converting enzyme (ACE) was isolatedand partially purifiedfrom the lungs of Wistarrats (Rattusnorvegicus). The ACE was characterized and its amino acids composition determined.ACE was purified by ammonium sulphate precipitation, dialysis and ge chromatography. The activity of the enzyme was assayed by a spectrophotometric method, which involves monitoring the rate of production of hippuric acid from the hydrolysis of Hippuryl Histidyl-L-Leucine by ACE.Protein concentration wasassay
more » ... entration wasassay optimum temperature and pH of the isolated enzyme were also determined. From the results, crude enzyme had a total activity of 0.12 U and a specific activity of 0.048U/mg of protein. Precipitation of protein increased the specific activity to 0.050U/mg at a recovery rate of 62%. Upon dialysis, the activity of the enzyme decreased from 0.074U to 0.038Uwhile specific activityalso increased. At this stage, only about 31% of the enzyme activity was retained over t crude. After gel filtration the specific activity of the enzyme increased to 0.087U/mg at a purification fold of 1.8 and a final recovery of 25%.The enzyme had an optimum pH and temperature of 7.0 and 40 0 C, respectively. The partially purified enzyme is havingseventeen amino acids:KHRDTSGPGACVMILYF. In conclusion, angiotensin-converting enzyme can be isolated from rat lungs, but the purification steps needs to be modified to obtain an enzyme with higher yield and assessable for research in developing countries. Angiotensin converting enzyme (ACE) was isolatedand partially purifiedfrom the lungs of Wistarrats (Rattusnorvegicus). The ACE was characterized and its amino acids composition determined.ACE was purified by ammonium sulphate precipitation, dialysis and ge chromatography. The activity of the enzyme was assayed by a spectrophotometric method, which involves monitoring the rate of production of hippuric acid from the hydrolysis of Hippuryl Leucine by ACE.Protein concentration wasassayed by Biuret method; amino acid content, optimum temperature and pH of the isolated enzyme were also determined. From the results, crude enzyme had a total activity of 0.12 U and a specific activity of 0.048U/mg of protein. increased the specific activity to 0.050U/mg at a recovery rate of 62%. Upon dialysis, the activity of the enzyme decreased from 0.074U to 0.038Uwhile specific activityalso increased. At this stage, only about 31% of the enzyme activity was retained over t crude. After gel filtration the specific activity of the enzyme increased to 0.087U/mg at a purification fold of 1.8 and a final recovery of 25%.The enzyme had an optimum pH and C, respectively. The partially purified enzyme is an oligopeptide havingseventeen amino acids:KHRDTSGPGACVMILYF. In conclusion, this study has shown that can be isolated from rat lungs, but the purification steps needs to be modified to obtain an enzyme with higher yield and specific activity that will be easily assessable for research in developing countries. Renin Angiotensin system, enzyme, rat lung
doi:10.4314/bajopas.v9i2.5 fatcat:6dlf5fh6fvbutjrvxo74n63dgu