Purification and characterization of tomato polygalacturonase converter

Pressey, Russell

doi:10.1111/j.1432-1033.1984.tb08452.x

Cited by 34 publications

(29 citation statements)

References 16 publications

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“…This result indicates that the antibody does not cross-react with PG2 and that the ft subunit is a part of the PGl isozyme. Chromatofocusing of the ft subunit indicated an isoelectric point of approximately 5.0 (data not shown), a value similar to that reported for fruit converter activity (Pressey, 1984a). This result accounted for the failure to detect free ft subunit in this immunoblot, because under these elecrrophoresis conditions it would not migrate into the gel.…”

Section: Preparation and Incubation Of Ripe Fruit Extractsmentioning

confidence: 52%

“…PG1 was dissociated in 8 M urea, 20 mM Na formate, pH 3.8, and the 0 subunit was isolated by chromatography 07 a Mono-S column using a linear gradient of 0.1 to 1.0 M NiiC1 in 8.0 M urea (United States Biochemical), 20 m Na formate, pH 3.8. Fractions were dialyzed against 1.0 M NaC1, 10.0 m Na formate, pH 3.8, to maintain solubility of the / 3 subunit (Pressey, 1984a). The use of silanized pipette tips and tubes was found to be essential to prevent nonspecific losses of purified 0 subunit.…”

Section: Purification Of Pg1 and The B Subunitmentioning

confidence: 99%

“…Tucker et al (1981) first described a heat-stable factor from green fruit tissue that could convert PG2 to a heat-stable PG1-like activity. Pressey (1984a) later partially purified and characterized this activity, which he termed the "converter," from ripe fruit and observed a much lower level of this activity in tomato leaf tissue. Knegt et al (1988) have also partially characterized a converter activity isolated from fruit extracts and from heat-denatured PG1 preparations.…”

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confidence: 99%

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Tomato Fruit Polygalacturonase Isozyme 1 (Characterization of the [beta] Subunit and Its State of Assembly in Vivo)

Moore¹,

Bennett²

1994

Plant Physiol.

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~Polygalacturonase isozyme 1 (PC1) is a heterodimer comprising a catalytic and noncatalytic or B subunit, whereas polygalacturonase isozyme 2 (PC2) comprises only the catalytic subunit. To assess the state of assembly of PCI in vivo, both subunits were purified to homogeneity and used to study assembly of the heterodimer.PC1 could be reconstituted in vitro from purified B subunit and purified PC2 under a wide range of salt and pH conditions, and PC1 reconstituted in vitro was indistinguishable from PC1 isolated from tomato (Lycopersicon esculentum) fruit. Specific antibodies indicated that the B subunit was present in fruit of all developmental stages, but absent in vegetative tissue. l h e state of assembly of PC1 in vivo was tested based on the differential thermal stability of PC1 and PC2 by heating segments of ripe fruit pericarp tissue. Temperatures well below those required to inactivate PC1 in vitro caused the loss of activity of both PC1 and PC2, suggesting that only heat-labile PC2 is present in vivo. In addition, when extracts of ripe fruit were rigorously maintained and analyzed at 4"C, PC1 was absent or barely detectable. These results are consistent with the hypothesis that PG1 can assemble spontaneously and i s essentially absent in intact tomato fruit but forms artifactually from PG2 and the B subunit during the extraction of tomato fruit tissue when low temperatures are not rigorously maintained.

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Section: Preparation and Incubation Of Ripe Fruit Extractsmentioning

confidence: 52%

Section: Purification Of Pg1 and The B Subunitmentioning

confidence: 99%

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confidence: 99%

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Tomato Fruit Polygalacturonase Isozyme 1 (Characterization of the [beta] Subunit and Its State of Assembly in Vivo)

Moore¹,

Bennett²

1994

Plant Physiol.

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“…a~b: Mean with the same superscript in a row are significantly different at p<0.05 Polygalacturonase는 대부분의 과실에 존재하며 연화와 가 장 밀접한 관계가 있으며, 성숙과 연화 중에 활성이 증가한 다고 하였다 (Tucker 1980;Hubr 1983;Pressey 1984). 세포 벽 middle lamella를 구성하는 pectin질을 분해하여 가용성 polyuronide로 유리시키고 동시에 pentin질의 side chain의 구성당인 galactose와 arabinose를 유리시킴으로써 연화를 촉 진 시킨다고 하였다 (Lamport 1971;Aspinall 1980 3) 가지장아찌의 소금 절임농도의 pH의 결과를 살펴보면 1%의 소금 절임농도의 장아찌보다 5%의 소금 농도로 절여 진 가지장아찌의 pH가 낮게 나타났다.…”

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Changes in Quality Characteristics of Eggplant Pickles by Salt Content and Drying Time during Storage

Choi¹,

Cho²

2012

Journal of the Korean Society of Food Culture

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Eggplant pickles were classified into three groups based on salt concentration (1, 3, 5%) and three groups based on drying time (30, 60 and 120 minutes), followed by storage at 5 o C for 28 days. Raw eggplant contains 94.82% water content. The increase in salt concentration and drying time caused a decrease in the moisture content. Compared to the 0.27% ash content of raw eggplant, the ash content of eggplant pickles increased noticeably with increasing salt concentration due to penetration into the eggplant pickles. pH values decreased significantly as the levels of salt concentration and dying time increased (p<0.05). In terms of storage time, pH values decreased from 21 days. The variation in salinity increased significantly as the concentration of salt increased. Compared to normal pickles salted at 5.39% salinity, eggplant pickles constituted 0.27~0.77% (1%), 0.40~1.14% (3%), and 0.47~11.20% (5%) 'low-salinity' eggplant pickles. Reducing-sugar content differed on the dates of 7, 14 and 21 in drying time and at 3% salinity. Hardness differed at 30, 60, and 120M on the 28th and 1, 5% salt concentration. Resilience differed according to drying time and from dates of 0 to 14th. The number of total microbes decreased at low salinity. In terms of storage time, the number of microbes tended to decrease after the 21st. In the consumer preference test, lightness of 5%-30M was the highest value.

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“…Hydrolytic enzymes involved in pectin depolymerization, including endo-and exogalacturonases, have been identified in numerous plant tissues, including pollen tubes (31), fruits (32), seeds (12), floral and leaf tissues (14), and stem (33). Thus, free GalA formed by depolymerization of pectic polysaccharides present in plant organs and storage tissues may provide an immediate non-photosynthetic source of carbon that enters the sugar nucleotide pathway.…”

Section: Enzyme Mutation Site Sugar Substratementioning

confidence: 99%

Identification of Galacturonic Acid-1-phosphate Kinase, a New Member of the GHMP Kinase Superfamily in Plants, and Comparison with Galactose-1-phosphate Kinase

Yang

Bar-Peled²,

Gebhart

et al. 2009

Journal of Biological Chemistry

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The process of salvaging sugars released from extracellular matrix, during plant cell growth and development, is not well understood, and many molecular components remain to be identified. Here we identify and functionally characterize a unique Arabidopsis gene encoding an ␣-D-galacturonic acid-1-phosphate kinase (GalAK) and compare it with galactokinase. The GalAK gene appeared to be expressed in all tissues implicating that glycose salvage is a common catabolic pathway. GalAK catalyzes the ATP-dependent conversion of ␣-D-galacturonic acid (D-GalA) to ␣-D-galacturonic acid-1-phosphate (GalA-1-P). This sugar phosphate is then converted to UDPGalA by a UDP-sugar pyrophosphorylase as determined by a real-time 1 H NMR-based assay. GalAK is a distinct member of the GHMP kinase family that includes galactokinase (G), homoserine kinase (H), mevalonate kinase (M), and phosphomevalonate kinase (P). Although these kinases have conserved motifs for sugar binding, nucleotide binding, and catalysis, they do have subtle difference. For example, GalAK has an additional domain near the sugar-binding motif. Using site-directed mutagenesis we established that mutation in A368S reduces phosphorylation activity by 40%; A41E mutation completely abolishes GalAK activity; Y250F alters sugar specificity and allows phosphorylation of D-glucuronic acid, the 4-epimer of GalA. Unlike many plant genes that undergo duplication, GalAK occurs as a single copy gene in vascular plants. We suggest that GalAK generates GalA-1-P from the salvaged GalA that is released during growth-dependent cell wall restructuring, or from storage tissue. The GalA-1-P itself is then available for use in the formation of UDP-GalA required for glycan synthesis.3 is a quantitatively major glycose present in numerous plant polysaccharides including pectins and arabinogalactan proteins (1, 2). The synthesis of these polysaccharides requires a large number of glycosyltransferases and diverse nucleotide-sugar (NDP-sugar) donors (1, 3). Some of these NDP-sugars are formed by interconversion of pre-existing NDP-sugars and by salvage pathways. For example, the main pathway for UDP-GalA formation is the 4-epimerization of UDP-GlcA, a reaction catalyzed by UDP-GlcA 4-epimerase (4 -6). However, in ripening Fragaria fruit D-GalA is incorporated into pectin (7). It is likely that a sugar kinase converts the D-GalA to GalA-1-P (8), which is then converted to UDP-GalA by a nonspecific UDP-sugar pyrophosphorylase (9). Myo-inositol may also be a source of GalA for polysaccharide biosynthesis (10).Galacturonic acid is likely to be generated by enzyme-catalyzed hydrolysis of pectic polysaccharides in plant tissues. Polysaccharide hydrolase activities are present in germinating seeds (11, 12), in germinating and elongating pollen (13-15), and in ripening fruit (14). Thus, monosaccharide salvage pathways may be required for normal plant growth and development.Numerous sugar-1-P kinases, including D-Gal-1-P kinase (16), L-Ara-1-P kinase (17), and L-Fuc-1-P kinase (18), have been describ...

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Purification and characterization of tomato polygalacturonase converter

Cited by 34 publications

References 16 publications

Tomato Fruit Polygalacturonase Isozyme 1 (Characterization of the [beta] Subunit and Its State of Assembly in Vivo)

Tomato Fruit Polygalacturonase Isozyme 1 (Characterization of the [beta] Subunit and Its State of Assembly in Vivo)

Changes in Quality Characteristics of Eggplant Pickles by Salt Content and Drying Time during Storage

Identification of Galacturonic Acid-1-phosphate Kinase, a New Member of the GHMP Kinase Superfamily in Plants, and Comparison with Galactose-1-phosphate Kinase

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