Multiple forms of phenol oxidase from Kolkhida tea leaves (Camelia Sinensis L.) and Mycelia Sterilia IBR 35219/2 and their role in tea production

Purification and characterization of catechol oxidase from Posof Badele apple (Malus domestica L): in vitro and in silico studies

In the current study, polyphenol oxidase (PPO), responsible for enzymatic browning in fruits, was purified from Posof Badele apple (PB) (Malus domestica L.) in two steps as acetone precipitation and affinity chromatography. After purification, the purity of PBPPO was checked by using SDS-PAGE. It was figured out that PBPPO had maximum activity at pH 6.0 and 10 °C and it was stable at pH 5.5 and temperatures of 0–30 °C. Besides, it was determined that Al3+ and Cu2+ metal ions activated the enzyme and the PBPPO was strongly inhibited by ascorbic acid with a Ki constant of 1.67 ± 0.35 µM. Inhibitor-enzyme interactions were examined by molecular docking studies and it was revealed that ascorbic acid had the lowest docking score of −6.54 kcal/mol. We wanted to draw attention to the PB apple, which is red inside as well as outside and very rich in terms of nutrient content.

Prokaryotic expression and purification of Camellia sinensis polyphenol oxidase

BACKGROUND

Polyphenol oxidase (PPO) causes the postharvest loss of fruits and vegetables but is also a key factor in the quality development of tea. However, there are no reports on engineered active plant PPO purified from prokaryotic cells.

RESULTS

In this study the ppo gene of about 1800 bp from Camellia sinensis cv. Yihongzao was successfully cloned and expressed in Escherichia coli. The PPOs purified from both the soluble fraction and the inclusion bodies showed activity. In addition, 1.0 × 10(-7) mol L(-1) Cu(2+) and acidic conditions were found to be favourable for the engineered PPO catalysis of catechol oxidation.

CONCLUSION

This paper represents the first report on C. sinensis ppo expression in E. coli and engineered active PPO purification. The results of the study provide a basis for the large-scale preparation and application of PPO.