Partial purification and kinetic characterization of mushroom stem polyphenoloxidase and determination of its storage stability in different lyophilized forms

Abstract

Monophenolase (1011 AE 626 U/g AP) and diphenolase activities (5163 AE 3059 U/g AP) of PPO in acetone powders (APs) of different mushroom stems varied considerably. However, the limited variation of average dipenolase (L-DOPA) to monophenolase (L-tyrosine) activity ratio (5.4 AE 0.7) in crude extracts showed the homogeneity of PPO from different mushroom stems. The change in extraction material or partial purification method (ammonium sulfate or acetone precipitation) did not affect the temperature stability, temperature and pH dependency and K m of monophenolase activity considerably. However, some changes were observed in pH stability and substrate specificity of PPO in different parties of mushroom stems. The most important aspects of mushroom stem PPO are its lower diphenolase to monophenolase activity ratio than mushroom cap PPO, low temperature dependency of activity between 25 and 40 8C (E a = 30 kJ/mol), broad optimum pH between 6 and 8, but lack of activity pH 5, and ability to use phloridzin as substrate. The mushroom stem PPOs partially purified and lyophilized by using sucrose, dextran or alginate showed moderate to high stability at À18 8C for 6-6.5 months. Thus, the mushroom stems obtained as a waste material during mushroom processing may be used as a more homogenous source than whole mushrooms to obtain PPO used for different industrial, clinical or research purposes. #

Effectivity of tyrosinase purification by membrane techniques versus fractionation by salting out

“…It seems that Agaricus bisporus tyrosinase should be regarded as the source of choice, mainly due to its availability (Seo et al 2003). Moreover, there are several reports related to the isolation and purification of tyrosinase from A. bisporus (Bouchilloux et al 1963;Duckworth and Coleman, 1970;Fan and Flurkey 2004;Gąsowska et al 2004;Gouzi and Benmansour 2007;Khan et al 2005;Lopez-Tejedor and Palomo 2018;Papa et al 1994;Simsek and Yemenicioglu 2007;Smith and Krueger 1962;Wichers et al 1996). Each method of tyrosinase purification involved three main steps: (i) cell disruption, (ii) removal of undesired low and high molecular weight compounds, and (iii) several kinds of chromatography.…”

Preparation, characterization and reusability efficacy of amine-functionalized graphene oxide-polyphenol oxidase complex for removal of phenol from aqueous phase

“…6 Laccases and tyrosinases are subgroups of polyphenol oxidase, utilizes molecular oxygen to convert phenolic compounds to quinones. 7,8 Both enzymes are metallic proteins with copper in their catalytic sites. 9,10 Mukherjee et al 11 comprehensively described the remediation of phenol using PPO, an enzyme found naturally in apples, bananas, grapes, mushrooms, lettuce and other fruits.…”