Purification and Characterization of a Polyphenol Oxidase from the Seeds of Field Bean (<i>Dolichos lablab</i>)

Paul, Beena; Gowda, Lalitha R.

doi:10.1021/jf000296s

Cited by 78 publications

(83 citation statements)

References 48 publications

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“…Differences in the type and degree of inhibition of various PPOs were reported. Guanata et al (1987) observed a competitive-type inhibition for grape PPO with cinnamic and benzoic acid inhibitors using 4-methylcatechol as a substrate; Dogan and Dogan (2004) for Thymus PPO with glutathione inhibitor using 4-methylcatechol, pyrogallol and catechol as substrates; Paul and Gowda (2000) for field bean PPO with tropolone, ascorbic acid, and cysteine-HCl inhibitors using catechol as a substrate; and Robert et al (1997) for palmito PPO with benzoic acid inhibitor using 4-methylcatechol as a substrate, and Aydemir (2010) for rosemary PPO with ascorbic acid and l-cysteine inhibitor using catechol as a substrate. In mixed inhibition, the inhibitor binds to both the enzyme itself and the ES complex yielding two K i constants.…”

Section: Effects Of Inhibitorsmentioning

confidence: 99%

Characterisation of polyphenol oxidase from Melissa officinalis L. subsp. officinalis (lemon balm)

Doğan¹,

Ayyıldız²,

Doğan³

et al. 2013

Czech J. Food Sci.

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Polyphenol oxidase (PPO) from Melissa officinalis L. subsp. officinalis (lemon balm) was partially purified by ammonium sulphate precipitation and dialysis; and then it was characterised in detail in terms of pH and temperature optima, thermal stability, kinetic parameters, and inhibition properties. Based on experimental results, it was found out that (i) the optimum pH and temperature values of PPO were 6.5, 4.0, and 8.5 and 40, 50, and 60°C for catechol, 4-methylcatechol and pyrogallol substrates, respectively; (ii) the best substrate was pyrogallol due to the highest V max /K m value, followed by catechol and 4-methylcatechol; (iii) enzyme activity decreased due to heat denaturation of the enzyme with increasing temperature and inactivation time for all substrates; (vi) gallic acid and l-glutamic acid did not inhibit PPO; and (v) the most effective inhibitor was glutathione. Furthermore, the phenolic and protein contents of lemon balm extract were also determined according to the Folin-Ciocalteu and Bradford methods, respectively.

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Section: Effects Of Inhibitorsmentioning

confidence: 99%

Characterisation of polyphenol oxidase from Melissa officinalis L. subsp. officinalis (lemon balm)

Doğan¹,

Ayyıldız²,

Doğan³

et al. 2013

Czech J. Food Sci.

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“…CO was first isolated by Kubowitz in 1937 from potatoes. [5,6] Since then COs have been purified from different sources, among which are potatoes, spinach, apples, grape berries, [7] lychee fruit, [8] beans, [9] bananas, [10] opium plants, [11] coffee plants, [12] black poplars, [13] and gypsy wort. [13] A new insight into the catalytic mechanism of catechol oxidases was gained with the determination of the crystal structure of the enzyme from sweet potatoes (Ipomoea batatas; ibCO).…”

Section: Introductionmentioning

confidence: 99%

Less Symmetrical Dicopper(II) Complexes as Catechol Oxidase Models—An Adjacent Thioether Group Increases Catecholase Activity

Merkel

Möller

Piacenza

et al. 2005

Chemistry A European J

124

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Three new unsymmetrical compartmental dinucleating ligands, 4-bromo-2-(4-methylpiperazin-1-ylmethyl)-6-[{2-(1-piperidyl)ethyl}aminomethyl]phenol (HL1), 4-bromo-2-(4-methylpiperazin-1-ylmethyl)-6-[{2-(morpholin-4-yl)ethyl}aminomethyl]phenol (HL2), and 4-bromo-2-(4-methylpiperazin-1-ylmethyl)-6-[{2-(thiomorpholin-4-yl)ethyl}aminomethyl]phenol (HL3), have been synthesized in order to model the active site of type 3 copper proteins. The dicopper(II) complexes of these ligands give first hints about the influence of a thioether group close to the metal site. The bromophenol-based ligands have one piperazine arm and one other bidentate arm in positions 2 and 6 of the phenolic ring, respectively. With each ligand a dinuclear copper(II) complex was prepared and structurally characterized. The copper ions were found to have square pyramidal environments and a mixture of endogenous phenoxo and exogenous acetate bridging. The influence of a heteroatom in one arm of the ligand on catecholase activity and speciation in solution was studied by UV/Vis spectroscopy, ESI-MS experiments and, DFT calculations.

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“…In the earlier studies Kavrayan and Aydemir (2001), Siddiq and Cash (2000), Paul and Gowda (2000), Das et al (1997) reported sodium metabisulfite as the most effective inhibitor against peppermint, pears, field bean and pineapple fruit PPO, respectively. A strong inhibitory effect of SO 2 on soursop PPO at pH 7.5 was also observed in our study.…”

Section: Metabisulphitementioning

confidence: 97%

“…A wide range of pH optima for the activity of PPO ranging from 4.0 (Paul and Gowda, 2000) in field bean seed to 8.5 (Seol et al, 1999) in ginkgo biloba leaves has been reported in literature. The soursop PPO activity as a function of pH is shown in Figure 1 The results of the PPO activity in partially purified enzyme extract in the temperature range of 10 to 50 º C are shown in Figure 2.…”

Section: Optimum Phmentioning

confidence: 99%

CHARACTERIZATION OF POLYPHENOL OXIDASE OF SOURSOP (Annona muricataL.) FRUIT AND A COMPARATIVE STUDY OF ITS INHIBITION IN ENZYME EXTRACT AND IN PULP CARACTERIZACIÓN DE POLIFENOLOXIDASA DE FRUTOS DE GUANÁBANA (Annona muricata L.) Y ESTUDIO COMPARATIVO DE SU INHIBICIÓN EN EXTRACTOS DE ENZIMA Y EN PULPA CARACTERIZACIÓN DE POLIFENOLOXIDASA DE FROITOS DE GUANÁBANA (Annona muricata L.) E ESTUDIO COMPARATIVO DA SÚA INHIBICIÓN EN EXTRACTOS DE ENZIMA E EN PULPA

Bora

Holschuh

Vasconcelos

2004

Ciencia y Tecnologia Alimentaria

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Crude enzyme extract containing polyphenoloxidase (PPO) was obtained from ripe soursop (Annona muricata L.) fruit by extraction with 0.2 M phosphate buffer (pH 7.5) containing 0.5 M NaCl, followed by precipitation with 20, 40, 60 and 80% saturation of ammonium sulfate and dialysis against distilled water at 4ºC. The maximum PPO activity was observed in the protein fraction obtained with 60% ammonium sulphate saturation. The effect of pH (3 to 8.8), temperature (20 to 60ºC) and chemical inhibitors (ascorbic acid, EDTA and SO 2 ) at several concentrations on the PPO activity was studied. The optimum pH and temperature for PPO activity were 7.5 and 32ºC, respectively. Among chemical inhibitors, ascorbic acid and SO 2 were almost equally effective, but EDTA showed very small inhibitory effect. 61.9 and 71.5% inhibition of PPO was achieved using 0.28 mM and 0.84 mM concentrations of ascorbic acid, while for 55.4 and 70.2% inhibition 0.78 mM and 2.34 mM concentrations of SO 2 were needed. Heating the enzyme extract at 70, 80, 90 and 95ºC for 6 s reduced 15.2, 49.5, 84.8 and 95.1% PPO activity, respectively. At the natural pH of pulp (4.3), SO 2 at concentration of 3.9 mM reduced specific activity of PPO from about 60 to about 8.4 U/mg protein in partially-purified enzyme extract (PPEE), while the specific activity of 22.5 U/mg protein was retained in the pulp. Heating PPEE at 80ºC at pH 4.3 (natural pH of pulp) for about 14 s decreased specific enzyme activity from 60.0 to about 11.0 U/mg and heating during 8 min decreased to 9.0 U/mg protein. ResumenSe obtuvo un extracto crudo de enzima conteniendo polifenoloxidasas (PPO) de frutos maduros de Guanábana (Annona muricata L.) por extracción con 0,2 M tampón fosfato (pH 7,5) conteniendo 0,5 M NaCl, seguido de precipitación con 20, 40, 60 y 80% de saturación de sulfato amónico y diálisis con agua destilada a 4ºC. El máximo de actividad de PPO se observó en la fracción de proteína obtenida con 60% de saturación sulfato amónico. Se estudió el efecto del pH (3 a 8,8), temperatura (20 a 60ºC) y inhibidores químicos (ácido ascórbico, EDTA y SO 2 ) a varias concentraciones, sobre la actividad de PPO. Los óptimos de pH y temperatura para la actividad de PPO fueron 7,5 y 32ºC, respectivamente. Mientras que para los inhibidores químicos, ácido ascórbico y SO 2 fueron casi igual de efectivos, pero EDTA mostró un bajo efecto inhibidor.Se obtuvo un 61,9 y 71,5% de inhibición de PPO con 0,28 mM y 0,84 mM de concentración de ácido ascórbico, mientras que con 0,78 mM y 2,34 mM de concentración de SO 2 obtuvo un 55,4 y 70,2% de inhibición, respectivamente. Calentando el extracto enzimático a 70, 80, 90 y 95ºC durante 6 s, se redujo a 15,2, 49,5, 84,8 y 95,1% la actividad de PPO, respectivamente. Al pH natural de la pulpa (4,3), SO 2 a la concentración del extracto enzimático 3,9 mM redujo la actividad específica de PPO desde 60 a 8,4 U/mg proteína en extracto enzimático parcialmente purificado (PPEE), mientras que en la pulpa la actividad específica se retuvieron 22,5 U/mg de pr...

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Purification and Characterization of a Polyphenol Oxidase from the Seeds of Field Bean (Dolichos lablab)

Cited by 78 publications

References 48 publications

Characterisation of polyphenol oxidase from Melissa officinalis L. subsp. officinalis (lemon balm)

Characterisation of polyphenol oxidase from Melissa officinalis L. subsp. officinalis (lemon balm)

Less Symmetrical Dicopper(II) Complexes as Catechol Oxidase Models—An Adjacent Thioether Group Increases Catecholase Activity

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