Multiple forms of pectinesterase in limes and oranges

Evans, Roger; McHale, D.

doi:10.1016/s0031-9422(00)94291-2

Cited by 42 publications

(26 citation statements)

References 4 publications

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“…Distribution of PME in orange has been investigated by Evans and McHale (1968) and Rombouts et al (1982) by analyses of extracts prepared from albedo and avedo, juice sacs and segment covers (-lamellae). The level of enzyme activity was 3 times higher in the juice sacs and the segment covers than that found in the extract of albedo and¯avedo.…”

Section: Discussionmentioning

confidence: 99%

Pectin methyl esterase from orange fruit: characterization and localization by in-situ hybridization and immunohistochemistry

Christensen¹,

Nielsen²,

Kreiberg³

et al. 1998

Planta

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Pectin methyl esterase (PME) from orange (Citrus sinensis L.) fruit peels has been purified by ammonium sulphate precipitation, and ion-exchange and gel-filtration chromatography. Characterization of the enzyme revealed a 36-kDa protein with an isoelectric point > 9, a pH optimum at 7 and temperature optimum at 50 degrees C. The substrate specificity and kinetic experiments showed that the affinity of PME for pectin was highly dependent on the degree of esterification (DE) of the pectin, with K(m) values of 0.7 mg ml-1 for pectin with a DE of 70% and 17 mg ml-1 for pectin with a DE of 25%. The sequences of the NH2-terminal end of digested peptides from the mature protein were obtained. A DNA fragment of 501 bp was cloned by polymerase chain reaction amplification using degenerate primers and was further used for screening of a cDNA library. Two cDNA clones were isolated encoding PMEs of 584 amino acids and 362 amino acids, respectively, including a putative signal peptide. The deduced amino acid sequence showed full identity to the sequenced peptides. Polyclonal antibodies raised against orange peel PME were used for immunohistochemistry. The main localization of PMEs was in the outer cell layers of the juice vesicles, in the outer cell layers of the lamellae between the segments and in the inner cell layers of the albedo in the peel. In-situ hybridization showed that the mRNA is very abundant in the fruit and was found in the same cell layers as the native enzyme. A very intensive staining for PME mRNA was also seen in the core and in the flavedo close to the oil glands.

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Section: Discussionmentioning

confidence: 99%

Pectin methyl esterase from orange fruit: characterization and localization by in-situ hybridization and immunohistochemistry

Christensen¹,

Nielsen²,

Kreiberg³

et al. 1998

Planta

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“…PME has been extracted and/or purified from different sources: e.g., tomatoes (23,(26)(27)(28)(29)(30)(31)(32)(33), oranges (18,21,(34)(35)(36)(37)(38)(39)(40), apples (17,24,(41)(42)(43)(44)(45)(46), grapefruits (22,47,48), and bananas (49)(50)(51). Biochemical properties, thermal stability and food applications of PME from these sources were reported in more or less details by several authors.…”

Section: Introductionmentioning

confidence: 99%

Partial Purification, Characterization, and Thermal and High-Pressure Inactivation of Pectin Methylesterase from Carrots (DaucuscarrotaL.)

Nguyen

Loey

Fachin

et al. 2002

J. Agric. Food Chem.

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Pectin methylesterase (PME) from carrots (Daucus carrota L.) was extracted and purified by affinity chromatography on a CNBr-Sepharose 4B-PME inhibitor column. A single protein and PME activity peak was obtained. A biochemical characterization in terms of molar mass (MM), isoelectric points (pI), and kinetic parameters of carrot PME was performed. In a second step, the thermal and high-pressure stability of the enzyme was studied. Isothermal and combined isothermal-isobaric inactivation of purified carrot PME could be described by a fractional-conversion model.

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“…A better understanding of such results was achieved when two forms of PE were separated from limes (Evans and McHale, 1968) and navel oranges (Versteeg et al, 1978). A high molecular weight, heat stable isozyme (HMW-PE) was identified by Versteeg (1979).…”

Section: Introductionmentioning

confidence: 99%

Total and Thermostable Pectinesterases in Citrus Juices

Snir

Koehler

Sims

et al. 1996

Journal of Food Science

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Grapefruits, tangerines and several orange cultivars were evaluated for total and thermostable pectinesterase (TS-PE) activity. Juices were extracted with a Fresh'n Squeeze Multi Fruit Juicer. Variation in total pectinesterase (PE) and TS-PE was not significantly different between cultivars. No significant contribution by traditional quality control parameters (%pulp, ЊBrix, % acid, pH), to total PE or TS-PE was observed. Positive correlations were observed between TS-PE and total PE, when expressed on a pulp (0.669) or soluble solids (0.624) basis.

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Multiple forms of pectinesterase in limes and oranges

Cited by 42 publications

References 4 publications

Pectin methyl esterase from orange fruit: characterization and localization by in-situ hybridization and immunohistochemistry

Pectin methyl esterase from orange fruit: characterization and localization by in-situ hybridization and immunohistochemistry

Partial Purification, Characterization, and Thermal and High-Pressure Inactivation of Pectin Methylesterase from Carrots (DaucuscarrotaL.)

Total and Thermostable Pectinesterases in Citrus Juices

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