Distribution and Characteristics of Polyphenoloxidase from Pacific White Shrimp (Litopenaeus vannamei).

Abstract

Distribution of polyphenoloxidase (PPO) from different anatomical parts of Pacific white shrimp was examined. Among all parts, cephalothorax possessed the maximal PPO activity (P < 0.05), followed by pereopods, telson, pleopods, carapace, cuticle, and muscle, respectively. The higher PPO activity in cephalothorax was in line with the greater melanosis in this part during chilled storage. According to activity-staining toward 3,4-dihydroxy-ʟ-phenylalanine (ʟ-DOPA), PPO exhibited an activity band with a molecular weight (MW) of 210 kDa. When cephalothorax PPO was purified using ammonium sulfate precipitation and a series of chromatographic techniques, involving DEAE-Sepharose anion exchange and Sephadex G-75 gel filtration columns, homogeneity was obtained. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and native-PAGE, the Sephadex G-75 fraction showed a single band. The MW band on SDS-PAGE and gel filtration was estimated as 210 kDa, suggesting a monomeric molecule. For the inhibitor study, cysteine and 4-hexylresorcinol showed competitive inhibition toward PPO, while epigallocatechin gallate and kojic acid demonstrated mixed-type inhibition toward PPO. PRACTICAL APPLICATION: Melanosis (black spot formation) triggered by polyphenoloxidase (PPO) drastically reduces the shelf-life of shrimp. PPO was localized in several anatomical parts of Pacific white shrimp with varying activities. Certain compounds, including cysteine, 4-hexylresorcinol, epigallocatechin gallate, and kojic acid, showed PPO inhibitory activity with different modes of inhibition. The obtained information provided a promising method for manufacturers to keep the prime eating quality of Pacific white shrimp throughout postmortem transportation and storage using selected PPO inhibitors.

• Authors: Thanasak Sae-Leaw, Soottawat Benjakul
• Journal: Journal of food science (J Food Sci) Vol. 84 Issue 5 Pg. 1078-1086 (May 2019) ISSN: 1750-3841 [Electronic] United States
• PMID: 30958915 (Publication Type: Journal Article)
• Copyright: © 2019 Institute of Food Technologists®.

Chemical References

• Catechol Oxidase

Topics

• Animals
• Catechol Oxidase (analysis, chemistry, metabolism)
• Penaeidae (enzymology)
• Seafood (analysis)
• Tissue Distribution