Purification and characterization of catechol oxidase from Tadela (Phoenix dactylifera L.) date fruit

Catechol oxidase (PPO) was extracted and purified from Tadela (Phoenix dactylifera L.) date fruit, by a procedure that included (NH4)2SO4 precipitation followed by dialysis, Q-Sepharose bb ion-exchange chromatography and HPLC gel filtration chromatography. Some of its biochemical characteristics wer...

Full description

Saved in:

Bibliographic Details
Published in:	International journal of biological macromolecules Vol. 125; pp. 1248 - 1256
Main Authors:	Benaceur, Farouk, Gouzi, Hicham, Meddah, Boumediene, Neifar, Aref, Guergouri, Ali
Format:	Journal Article
Language:	English
Published:	Netherlands Elsevier B.V 15-03-2019
Subjects:	Catechol Oxidase - antagonists & inhibitors Catechol Oxidase - chemistry Catechol Oxidase - isolation & purification Enzymatic browning Enzyme Activation Fruit - enzymology Hydrogen-Ion Concentration Kinetics Molecular Weight Phoeniceae - enzymology Plant Proteins - antagonists & inhibitors Plant Proteins - chemistry Plant Proteins - isolation & purification Purification and biochemical characterization Substrate Specificity Tadela catechol oxidase Temperature Thermodynamics Tadela catechol oxidase Enzymatic browning Purification and biochemical characterization
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Catechol oxidase (PPO) was extracted and purified from Tadela (Phoenix dactylifera L.) date fruit, by a procedure that included (NH4)2SO4 precipitation followed by dialysis, Q-Sepharose bb ion-exchange chromatography and HPLC gel filtration chromatography. Some of its biochemical characteristics were studied. The purification rate and the yield were 80% and 20%, respectively. The Tadela date fruit catechol oxidase exhibited a molecular weight of 90 kDa using SDS-PAGE. The catechol oxidase showed only o‑diphenolase and triphenolase activities while no monophenolase activity was detected. A better affinity was observed using catechol as substrate (Km = 35 mM) with thus, a higher Vmax/Km ratio (80 U/mM·mL). This enzyme is thermostable in the temperature range (30–60 °C) with optimum activity in acidic range of pH. Four inhibitors were used for the control of enzymatic browning, of which sodium metabisulfite was the most potent (IC50 = 0, 11 mM). The values of KI and mechanism of inhibition were also determined. No significant change on enzyme activity was noticed in the presence of metal ion and detergents. Therefore, thermal inactivation was studied in the temperature range between 60 and 80 °C using catechol as substrate. Their kinetic (K, D, t1/2, Zt, Ea) and thermodynamic (ΔH, ΔG and ΔS) parameters were also estimated. •Catechol oxidase from Tadela date fruit was purified and characterized.•Sodium Metabisulfite, Sodium azide, l‑cysteine and ascorbic acid were excellent PPO inhibitors.•The Tadela catechol oxidase is a thermostable enzyme and its thermal inactivation was described by a first order reaction.•The sensitivity of enzyme towards temperature is amplified in presence of inhibitors.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0141-8130 1879-0003
DOI:	10.1016/j.ijbiomac.2018.09.101