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Purification and characterization of membrane-bound polyphenoloxidase (mPPO) from Snake fruit [Salacca zalacca (Gaertn.) Voss].


Mohd Zaini, Nurul Aqilah and Osman, Azizah and Abdul Hamid, Azizah and Ebrahimpour, Afshin and Saari, Nazamid (2013) Purification and characterization of membrane-bound polyphenoloxidase (mPPO) from Snake fruit [Salacca zalacca (Gaertn.) Voss]. Food Chemistry, 136 (2). pp. 407-414. ISSN 0308-8146


Membrane-bound polyphenoloxidase (mPPO) an oxidative enzyme which is responsible for the undesirable browning reaction in Snake fruit (Salacca zalacca (Gaertn.) Voss) was investigated. The enzyme was extracted using a non-ionic detergent (Triton X-114), followed by temperature-induced phase partitioning technique which resulted in two separate layers (detergent-poor phase at the upper layer and detergent-rich phase at the lower layer). The upper detergent-poor phase extract was subsequently fractionated by 40–80% ammonium sulfate and chromatographed on HiTrap Phenyl Sepharose and Superdex 200 HR 10/30. The mPPO was purified to 14.1 folds with a recovery of 12.35%. A single prominent protein band appeared on native-PAGE and SDS–PAGE implying that the mPPO is a monomeric protein with estimated molecular weight of 38 kDa. Characterization study showed that mPPO from Snake fruit was optimally active at pH 6.5, temperature 30 °C and active towards diphenols as substrates. The Km and Vmax values were calculated to be 5.46 mM and 0.98 U/ml/min, respectively, when catechol was used as substrate. Among the chemical inhibitors tested, l-cysteine showed the best inhibitory effect, with an IC50 of 1.3 ± 0.002 mM followed by ascorbic acid (1.5 ± 0.06 mM), glutathione (1.5 ± 0.07 mM), EDTA (100 ± 0.02 mM) and citric acid (186 ± 0.16 mM).

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Additional Metadata

Item Type: Article
Divisions: Faculty of Food Science and Technology
DOI Number: https://doi.org/10.1016/j.foodchem.2012.08.034
Publisher: Elsevier
Keywords: Snake fruit (Salacca zalacca); Membrane-bound polyphenoloxidase; Extraction; Purification; Characterization.
Depositing User: Khairil Ridzuan Khahirullah
Date Deposited: 14 Jul 2014 05:20
Last Modified: 07 Oct 2015 08:40
Altmetrics: http://www.altmetric.com/details.php?domain=psasir.upm.edu.my&doi=10.1016/j.foodchem.2012.08.034
URI: http://psasir.upm.edu.my/id/eprint/30443
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