Partial Purification of Polyphenol Oxidase (PPO) from Mango Seed Kernel(MSK) Using Alcohol/Salt-Based Aqueous Two-Phase System (ATPS)

Background: Polyphenol oxidase (PPO) has applications in pharmaceutical, environmental,and food industries. However, conventional techniques for its purification are consideredcostly and laborious. Alternative methods of purification are needed. Methods: This study explored the use of an alcohol/salt-based Aqueous Two-Phase System (ATPS)to partially purify PPO from Mango Seed Kernel (MSK). Specifically, this study determined theeffects of the 1-propanol/potassium phosphate buffer mass ratio on the partition parameters such aspartition coefficients, activity recovery, and purification fold. Results: The enzyme partition coefficient (KE) was greater than 1, which signified that more PPOwas partitioned in the top phase due to its hydrophobic nature. Specifically, the 3.22 1-propanol/PPB mass ratio had the highest K E of 1.91 ± 0.16 and 1.46 ± 0.16 for runs 1 and 2, respectively.Moreover, the same mass ratio led to the highest activity recovery in the top phase reachingup to 73.99 ± 1.56% for run 1 and 64.27 ± 2.48% for run 2. In terms of purification fold, runs 1 and2 had PF values of 0.55 ± 0.05 and 0.70 ± 0.01, respectively. Since the values obtained were lowdue to the large number of contaminants extracted together with the target enzyme in the top phase,the use of a back-extraction step recovered the PPO in the bottom phase and resulted in an activityrecovery of 82.94 ± 1.05% and a purification fold of 7.01 ± 0.95. Conclusion: Results have shown that varying the mass ratio had significant effects on the partitionparameters.