Polyphenol oxidase mediates (−)-epigallocatechin gallate to inhibit endogenous cathepsin activity in Apostichopus japonicus

• Published in: Food chemistry Vol. 449; p. 139166
• Main Authors: Guo, Yicheng, Ming, Yu, Sun, Kailing, Dong, Xiufang, Nakamura, Yoshimasa, Dong, Xiuping, Qi, Hang
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.08.2024
• Subjects: Animals; Catechin - analogs & derivatives; Catechin - chemistry; Catechin - pharmacology; Catechol Oxidase - chemistry; Catechol Oxidase - metabolism; Cathepsins - chemistry; Cathepsins - metabolism; EGCG; Endogenous enzyme; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - pharmacology; Enzyme Stability; Inhibitory activity; Kinetics; Polyphenol oxidase; Stichopus - chemistry; Stichopus - enzymology; Tyrosinase; Endogenous enzyme; EGCG; Tyrosinase; Polyphenol oxidase; Inhibitory activity
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139166

Apostichopus japonicus (A. japonicus) has rich nutritional value and is an important economic crop. Due to its rich endogenous enzyme system, fresh A. japonicus is prone to autolysis during market circulation and storage, resulting in economic losses. In order to alleviate this phenomenon, we investigated the effect of polyphenol oxidase (PPO) mediated (−)-epigallocatechin gallate (EGCG) on the activity and structure of endogenous cathepsin series protein (CEP) from A. japonicus. Research on cathepsin activity showed that PPO mediated EGCG could significantly reduce enzyme activity, resulting in a decrease in enzymatic reaction rate. SDS-PAGE and scanning electron microscopy results showed that PPO mediates EGCG could induce CEP aggregation to form protein aggregates. Various spectral results indicated that EGCG caused changes in the structure of CEP. Meanwhile, the conjugates formed by PPO mediated EGCG had lower thermal stability. In conclusion, PPO mediated EGCG was an effective method to inhibit the endogenous enzyme activity. [Display omitted] •Polyphenol oxidase mediates EGCG combined with endogenous cathepsin.•Polyphenol oxidase mediates EGCG induced structural changes of endogenous cathepsin.•Polyphenol oxidase mediates EGCG inhibited the activity of endogenous cathepsin.•Polyphenol oxidase mediates EGCG reduced thermal stability of endogenous cathepsin.