Purification and Properties of Polyphenol Oxidase of Dried Volvariella bombycina

SIMPLE SUMMARY: Mushrooms are non-green, edible fungi that are high in non-starchy carbohydrates, fiber, protein, minerals, and vitamins. Mushrooms have over a hundred different medicinal properties. Volvariella bombycina, an important wild, edible, and medicinal mushroom, has commercial cultivation potential. Polyphenol oxidases (PPOs), copper-containing metalloprotein enzymes that are widely distributed in microorganisms, plants, and animals, are responsible for melanization in animals and browning in plants. Mushrooms are commonly used as a potent PPO source because they can be obtained in relatively large amounts and are cheap. PPO was purified and characterized from dried V. bombycina, and it will also encourage researchers to perform further studies. PPO was purified and characterized for the first time from a dried wild edible and medicinal mushroom (V. bombycina). ABSTRACT: Polyphenol oxidase (PPO) was purified and characterized from a dried wild edible and medicinal mushroom (V. bombycina). Using Sepharose 4B-L-tyrosine-p-aminobenzoic acid affinity chromatography, PPO was purified from the dried V. bombycina. The purification was completed with a 33.85-fold purification. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the purified enzyme migrated as a single band. The molecular weight of the purified enzyme was estimated by SDS-PAGE to be about 25 kDa. Catechol, 4-methyl catechol, and pyrogallol were used as substrates to determine the enzyme activity and its kinetic parameters (Km and Vmax). At the optimum pH and temperature, dried V. bombycina PPO’s Km and Vmax values for catechol, 4-methyl catechol, and pyrogallol were found to be 1.67 mM–833.33 U/mL, 3.17 mM–158.73 U/mL, and 2.67 mM–3333.33 U/mL, respectively. Also investigated were the effects of pH and temperature on the enzymatic properties of PPO in dried V. bombycina. The optimum pH and temperature values for dried V. bombycina PPO obtained by using catechol, 4-methyl catechol, and pyrogallol as substrates were 6.5, 15 °C; 9.0, 20 °C; and 8.0, 15°C, respectively. This is the first study on the purification and characterization of PPO from dried V. bombycina.