Update on the source of phenoloxidase activity in the hemolymph of kuruma prawn Marsupenaeus japonicus

Crustacean phenoloxidase (PO) and hemocyanin (Hc) are classified as type 3 copper proteins. PO catalyzes the oxidation of mono- di-phenol compounds, which is rate-limiting step melanization, while Hc generally functions a dioxygen-transporting protein in hemolymph arthropods. To date, many studies have shown activity Hc, inspired by their structural similarity. Here, source crustaceans was re-examined purifying exclusively from kuruma prawn. The conventional procedure for preparation arthropod includes precipitation ultracentrifugation subsequent purification size exclusion chromatography, not able to completely remove hemolymph-type Hc. In contrast, fractionation with 50% saturation ammonium sulfate hydrophobic chromatography yielded sufficiently pure contained no detectable virtually enzymatic activity. These results indicate that main prawn improved method preferable evaluating