UJI AKTIVITAS ENZIM POLIFENOL OKSIDASE HASIL ISOLASI DENGAN PEMURNIAN PARSIAL DARI BUAH PHYSALIS PERUVIANA L.

• Main Author: Wijaya, Sendi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44753
• Institution: Institut Teknologi Bandung

Polyphenol oxidase (PPO) is a group of oxidoreductase enzymes which catalyze the oxidation of phenolic compounds using oxygen compounds. In agriculture, this enzyme is considered harmful because it can cause the browning of food products such as fruits and vegetables. The enzyme activity and the determination of enzyme kinetics parameters PPO assay was partially isolated from the fruit of Physalis peruviana L. / ceplukan. PPO enzyme activity and enzyme kinetics assay were tested using catechol substrate by measuring the formation of quinone using UV-Vis spectrophotometer. The maximum wavelength for measuring the activity of the PPO was 400 nm. It had the highest enzyme activity in pericarp part of the fruit. Among the substrates tested, catechol was the best substrate for testing the enzyme activity of fruit Physalis peruviana L. with concentration of 0.5 M. The pH and temperature optimum to assay the activity of PPO were pH 6.4 and 35 ° C respectively and incubation time for 5 minutes. PPO specific activity of fruit pericarp extract Physalis peruviana L. was 11.81 ± 0.057 units/mg, yield of precipitation with 70% ammonium sulfat saturated be 25.59 ± 0.110 unit/mg. The specific activity of PPO results dialysis was 25,58 ± 0,108 units/mg and after purified by ion exchange resin chromatography was 50.41 ± 1.170 units / mg. KM value and vmax of dialysate were 0.206 M and 0.043 M/min. From the inhibitor test, benzoic acid was a competitive inhibitor towards catechol substrate. PPO enzyme that partially isolated from the pericarp fruit of Physalis peruviana L. had specific activity 50.41 ± 1.170 units/mg and enzyme kinetic parameter KM was 0.206 M and vmax was 0.043 M/min.