Purification and characterization of latent polyphenol oxidase from truffles (Terfezia arenaria)

• Published in: International journal of biological macromolecules 2020-02, Vol.145, p.885-893
• Main Authors: Benaceur, Farouk, Chaibi, Rachid, Berrabah, Fethi, Neifar, Aref, Leboukh, Mourad, Benaceur, Kenza, Nouioua, Wafa, Rezzoug, Asmaa, Bouazzara, Houria, Gouzi, Hicham, Cabana, Hubert, Gargouri, Ali
• Format: Article
• Language: English
• Subjects: kojic acid.enzymatic browning; Polyphenol oxidase; Purification, characterization; Truffles
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2019.09.126

•Polyphenol oxidase from truffles was purified and characterized.•PPO showed best affinity for catechol as substrate and stability under wide range of pH and temperature.•Cu+2, SDS, sarkosyl and Triton X100 activate latent form of enzyme.•AL+3, Kojic acid, L-cysteine, Metabisulfite sodium and sodium fluoride were excellent PPO inhibitors.•Kojic acid amplify heat sensitivity of enzyme and reduce loss of antioxidant potential. The polyphenol oxidase was extracted and purified from truffles (Terfezia arenaria) and it exhibited a molecular weight of 67 kDa. The truffle PPO was able to oxidize monophenolic, o-diphenolic and triphenolic substrates. Thus, the enzyme seems to be stable under wide range of pH and temperature. Best catalytic efficiency was observed for catechol as substrate (Kcat/km; 674.2 S−1 mM−1).The effect of detergents, chaotropic agents, metal ions and eleven different inhibitors on relative activity of Truffles PPO was also investigated. A latent form of enzyme was observed and its activity was stimulated using 4 mM of SDS. Likewise, the type of inhibition and the values of KI and IC50 were reported for L-cysteine, Sodium fluoride, sodium metabisulfite and kojic acid. Besides, the effect of four concentrations of kojic acid(0.05.,0.1.,0.2 and 0.3 mM) on thermal inactivation of PPO was performed in temperature range “ 60–75° C”. The use of Kojic acid increase the rate of inactivation process and disrupt enzymatic activity. Moreover, the combined effect of temperature and kojic acid prevent from enzymatic browning reaction and maintain high antioxidant activities including ABTS scavenging activity, FRAP, and total phenolic contents.