Specificity of an o-diphenol oxidase from Prunus avium fruits

Lanzarini, G.; Pifferi, Pier Giorgio; Zamorani, Arturo

doi:10.1016/s0031-9422(00)89972-0

Cited by 32 publications

(11 citation statements)

References 20 publications

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“…PPO from various sources may possess both catechol oxidase and cresolase activity (15,23), only cresolase activity (27,28), or only catechol oxidase activity (18,24). In most cases where only catechol oxidase activity is apparent, cresolase activity can be initiated by the addition of reducing agents or catalytic amounts of an o-diphenol to the reaction (5,14,26).…”

Section: Substrate Specificitymentioning

confidence: 99%

Purification and Characterization of Polyphenol Oxidase from Glandular Trichomes of Solanum berthaultii

Kowalski¹,

Eannetta²,

Hirzel³

et al. 1992

Plant Physiol.

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Type A glandular trichomes of the wild potato (Solanum berthaultii Hawkes) entrap insects by rapidly polymerizing the trichome contents after breakage by insect contact. Polymerization of trichome exudate appears to be driven by a soluble polyphenol oxidase (PPO). PPO constitutes up to 70% of the protein in individually collected trichomes and reaches a concentration approaching 200 gM in these organs. Trichome PPO has been purified and shown to be a monomeric copper metalloprotein with an isoelectric point of 5.5, possessing only o-diphenol oxygen oxidoreductase activity, and is larger than most other reported PPOs, with relative molecular weight of 59,000. Chlorogenic and caffeic acid were the most readily oxidized of 14 phenolic substrates tested. Polyclonal antibodies raised against the relative molecular weight 59,000 S. berthaultii trichome PPO were used to show that S. tuberosum L. trichomes express low levels of a cross-reactive protein that lacks detectable PPO activity.The selection process that has given rise to the modem cultivated potato (Solanum tuberosum L.) has drastically narrowed its genetic base. A few genetically similar varieties now account for nearly all of the acreage grown in the United States. Selection for horticultural quality may have been accompanied by the inadvertent removal or reduction in levels of important pest-resistance factors (e.g. steroidal glycoalkaloids) (34), and until recently, relatively little success has been achieved toward breeding for resistance to insects that have adapted to cultivated potato (e.g. the Colorado potato beetle, Leptinotarsa decemlineata). Hence, it is not surprising that the cultivated potato is susceptible to attack from a wide array of arthropod herbivores; little inherent insect resistance remains in S. tuberosum. There is, however, a broad diversity of genetic traits available in wild germplasm. Wild potato species exhibit substantial resistance to insect pests. The wild Bolivian potato species Solanum berthaultii Hawkes displays a high degree of resistance to aphids, leafhoppers, flea beetles, spider mites, and the Colorado potato beetle (11). This resistance is conferred by high densities of foliar glandular trichomes (8,9,11).Glandular trichomes are modified epidermal cells that fre-

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Section: Substrate Specificitymentioning

confidence: 99%

Purification and Characterization of Polyphenol Oxidase from Glandular Trichomes of Solanum berthaultii

Kowalski¹,

Eannetta²,

Hirzel³

et al. 1992

Plant Physiol.

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“…PPOs catalyze two distinct reactions: the hydroxylation of monophenols to o-diphenols (cresolase, tyrosinase, or monophenol monooxygenase [EC1.14.18.1]) and the dehydrogenation of o-dihydroxyphenols to o-quinones (catecholase or diphenol oxygen oxidoreductase [EC 1.10.3.2]). PPOs may exhibit either or both of these activities [15,23,27,28,47], but typically the monophenol monooxygenase activity is labile or requires priming with reducing agents or small amounts of an o-diphenol. The quinonoid reaction products of PPO are strong electrophiles which autoxidize, forming melanin, and are also capable of covalently modifying and crosslinking a variety of cellular nucleophiles.…”

Section: Introductionmentioning

confidence: 99%

cDNA cloning and expression of potato polyphenol oxidase

et al. 1993

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Polyphenol oxidases (PPOs) of plants are copper metalloproteins which catalyze the oxidation of mono- and o-diphenols to o-diquinones. Although PPOs are believed to be primarily responsible for the deleterious browning of many fruit and vegetable crops and are thought to be involved in plant-pest interactions, direct evidence for these roles is lacking. We report the cloning of two PPO cDNAs from Solanum tuberosum leaves. These cDNAs exhibit 97% and 98% sequence similarity at the DNA and deduced amino acid levels, respectively. Putative copper-binding regions of both cDNAs are very similar to those of mammalian, bacterial and Neurospora tyrosinases. Both leaf PPO cDNAs appear to encode polypeptides which are processed to a mature molecular weight of 57,000. In potato leaves, petioles, roots, and flowers, PPO is encoded by ca. 2 kb transcripts. Leaf PPO mRNA is developmentally regulated and only detectable in young foliage. In contrast, the protein profile of immunologically detectable PPO remains constant from the apical node through the eleventh leaf node.

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“…The activity was determined spectophotometrically at 420 and 430 nm with the use of pyrocatechin and pyrogallol as sub strates, respectively, as described in the work [17].…”

Section: Methodsmentioning

confidence: 99%

Biochemical processes at the stage of withering during black tea production

Omiadze

Mchedlishvili

Rodrigez-Lopez

et al. 2014

Appl Biochem Microbiol

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We determined the molecular weight and some properties of multiple forms of phenol oxidase from tea leaves and four other perennial plants. It was shown that multiple high and low molecular forms of phenol oxidase differed in substrate specificity. Low molecular forms of the enzyme mostly demonstrated hydroxylase activity, while high molecular forms showed catechol oxidase activity. It was revealed that the withering stage of black tea production is accompanied by the formation of only high molecular forms of phenol oxidase, which possess catechol oxidase activity crucial for the procurement of oxidative reactions and the quality of the product.

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Specificity of an o-diphenol oxidase from Prunus avium fruits

Cited by 32 publications

References 20 publications

Purification and Characterization of Polyphenol Oxidase from Glandular Trichomes of Solanum berthaultii

Purification and Characterization of Polyphenol Oxidase from Glandular Trichomes of Solanum berthaultii

cDNA cloning and expression of potato polyphenol oxidase

Biochemical processes at the stage of withering during black tea production

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