Journal of Radiation Research and Radiation Proces ›› 2017, Vol. 35 ›› Issue (3): 30401-030401.doi: 10.11889/j.1000-3436.2017.rrj.35.030401

• RADIATION TECHNOLOGY APPLICATION • Previous Articles     Next Articles

Effects of electron beam irradiation on the activity and structure of tyrosine oxidase

GU Kefei1,2,3   

  1. 1 Institute for Agri-food Quality Standards and Technology SAAS, Shanghai 201304, China;
    2 Agricultural Products Quality and Safety Risk Assessment Laboratory M. O. A., Shanghai 201304, China;
    3 Supervision and Testing Center for Edible Fungi Quality, M. O. A., Shanghai 201403, China
  • Received:2017-03-14 Revised:2017-05-04 Online:2017-06-20 Published:2017-06-15
  • Supported by:

    Supported by the project of Shanghai Key Project of Science and Technology (hunongkekongzi (2009) No. 6-1), and the Risk of National Ministry of Agriculture of Agricultural Products Quality Safety Evaluation Project “edible fungi products nutrient and quality assessment and critical control point (GJFP201700604)”


The influence of electron beam irradiation on the activity and structure of PPO (Polyphenol oxidase) was analyzed. The results showed that electron beam irradiation can reduce PPO enzyme activity to a certain extent at a dose lower than 4.83 kGy. Analysis by circular dichroism (CD) showed that PPO protein's relative content of secondary structure affected by electron beam irradiation and total content of alpha helix, beta, and beta folding angle changed slightly. In contrast, at a dose higher than 4.83 kGy, the total content of the alpha helix, beta folding, and beta angle declined, and the random curl content increased. SDS-PAGE results showed that simultaneous cross-linking and degradation of the PPO enzyme occurred during irradiation. The experimental results indicate that electron beam irradiation can inhibit the activity of PPO.

Key words: Polyphenol oxidase, Electron beam irradiation, Protein structure

CLC Number: 

  • TL99