Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The purification and some properties of the polyphenol oxidase from tea (Camellia sinensis L.).

ABSTRACT: 1. Polyphenol oxidase (EC 1. 10. 3.-) from the shoots of the tea plant was purified about 5000-fold on a dry-weight basis. 2. At an intermediate stage of purification four soluble yellow fractions were obtained. They are believed to represent complexes of a basic enzyme protein with acidic phenolic oxidation products and nucleic acids. After removal of the complex-forming materials the fractions were blue and similar to each other. About 40% of the activity could not be extracted from the acetone-dried powder. 3. Each of the four blue fractions was resolved further into two species, A and B. The following results refer to species A. 4. The enzyme showed absorption maxima at 279mmu (E(1%) (1cm.), 13.5) and 611mmu (E(1%) (1cm.), 0.84) with a shoulder at 330mmu. The enzyme was bleached by substrate under anaerobic conditions and the colour was restored by oxygen. 5. The molecular weight measured by sedimentation and diffusion was 144000+/-16000. The copper content was 0.32% (w/w). 6. Kinetic constants are given for a number of substrates and inhibitors, including the natural substrates of the tea leaf. The specific activity towards pyrogallol was 373 units/mg. at 30 degrees . 7. The best substrates were o-dihydric phenols. Quinol and p-phenylenediamine were slowly oxidized. Monohydric phenols and ascorbic acid were not oxidized. 8. The kinetics of oxidation of most substrates are consistent with a mechanism in which oxidized and reduced forms of the enzyme form binary complexes with phenol and oxygen respectively. A modified mechanism is postulated for the oxidation of chlorogenic acid. 9. The relation of the results to the mechanism of tea fermentation is discussed.

SUBMITTER: Gregory RP

PROVIDER: S-EPMC1270155 | biostudies-other | 1966 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Purification of polyphenol oxidase from tea (Camellia sinensis) using three-phase partitioning with a green deep eutectic solvent

Project description: Not available

| S-EPMC11369402 | biostudies-literature

Two New Polyphenol Oxidase Genes of Tea Plant (Camellia sinensis) Respond Differentially to the Regurgitant of Tea Geometrid, Ectropis obliqua.

Project description:Polyphenol oxidases (PPOs) have been reported to play an important role in protecting plants from attacks by herbivores. Though PPO genes in other plants have been extensively studied, research on PPO genes in the tea plant (Camellia sinensis) is lacking. In particular, which members of the PPO gene family elicit the defense response of the tea plant are as yet unknown. Here, two new PPO genes, CsPPO1 and CsPPO2, both of which had high identity with PPOs from other plants, were obtained from tea leaves. The full length of CsPPO1 contained an open reading frame (ORF) of 1740 bp that encoded a protein of 579 amino acids, while CsPPO2 contained an ORF of 1788 bp that encoded a protein of 595 amino acids. The deduced CsPPO1 and CsPPO2 proteins had calculated molecular masses of 64.6 and 65.9 kDa; the isoelectric points were 6.94 and 6.48, respectively. The expression products of recombinant CsPPO1 and CsPPO2 in Escherichia coli were about 91 and 92 kDa, respectively, but the recombinant proteins existed in the form of an inclusion body. Whereas CsPPO1 is highly expressed in stems, CsPPO2 is highly expressed in roots. Further results showed that the expression of CsPPO1 and CsPPO2 was wound- and Ectropis obliqua-induced, and that regurgitant, unlike treatment with wounding plus deionized water, significantly upregulated the transcriptional expression of CsPPO2 but not of CsPPO1. The difference between regurgitant and wounding indicates that CsPPO2 may play a more meaningful defensive role against E. obliqua than CsPPO1. Meanwhile, we found the active component(s) of the regurgitant elicited by the expression of CsPPO may contain small molecules (under 3-kDa molecular weight). These conclusions advance the understanding of the biological function of two new PPO genes and show that one of these, CsPPO2, may be a promising gene for engineering tea plants that are resistant to E. obliqua.

| S-EPMC6121673 | biostudies-literature

The R2R3 Transcription Factor CsMYB59 Regulates Polyphenol Oxidase Gene <i>CsPPO1</i> in Tea Plants (<i>Camellia sinensis</i>).

Project description:Polyphenol oxidase (PPO) plays a role in stress response, secondary metabolism, and other physiological processes during plant growth and development, and is also a critical enzyme in black tea production. However, the regulatory mechanisms of PPO genes and their activity in tea plants are still unclear. In this study, we measured PPO activity in two different tea cultivars, Taoyuandaye (TYDY) and Bixiangzao (BXZ), which are commonly used to produce black tea and green tea, respectively. The expression pattern of CsPPO1 was assessed and validated via transcriptomics and quantitative polymerase chain reaction in both tea varieties. In addition, we isolated and identified an R2R3-MYB transcription factor CsMYB59 that may regulate CsPPO1 expression. CsMYB59 was found to be a nuclear protein, and its expression in tea leaves was positively correlated with CsPPO1 expression and PPO activity. Transcriptional activity analysis showed that CsMYB59 was a transcriptional activator, and the dual-luciferase assay indicated that CsMYB59 could activate the expression of CsPPO1 in tobacco leaves. In summary, our study demonstrates that CsMYB59 represents a transcriptional activator in tea plants and may mediate the regulation of PPO activity by activating CsPPO1 expression. These findings provide novel insights into the regulatory mechanism of PPO gene in Camellia sinensis, which might help to breed tea cultivars with high PPO activity.

| S-EPMC8600361 | biostudies-literature

Effects of light and darkness on polyphenol distribution in the tea plant (Camellia sinensis L.).

Project description:1. Flavonoid synthesis was able to proceed in darkness in young shoots and seedlings of the tea plant, but was increased by light. 2. The initial effect of darkness was to inhibit synthesis of the A ring or its linkage to the phenylpropane moiety of the flavonoid, but later the hydroxylation state of the flavanols was affected, leading to smaller proportions of gallocatechins and of complex leucoanthocyanins. 3. The esterification of catechins with gallic acid was less affected, so that the ratio of catechin gallates to simple catechins also increased. 4. The flavylogen content of darkened stems, especially in seedlings, was much less decreased than that of leaves; however, a short subsequent light-treatment caused an increase in polymerization.

| S-EPMC1184767 | biostudies-other

Studies on the polyphenol metabolism of tissue cultures derived from the tea pant (Camellia sinensis L.).

Project description:1. The growth characteristics on various media of solid and liquid suspension cultures derived from the stem of the tea plant are described; chlorophyll and anthocyanin synthesis occurred in the light. 2. Only the simplest catechins and leucoanthocyanins were present in callus tissue, although oligomeric and polymeric leucoanthocyanin fractions were also represented. Light caused an increase in all monomeric components analysed, but inhibited polymerization of the leucoanthocyanins. 3. The polyphenol oxidase activity of cultures was comparable with that of the apical regions of the intact plant, and was inversely correlated with growth rate. 4. Growth was stimulated by hormonal variation, and inhibited by high concentrations of sucrose and by high light-intensity; polyphenol concentrations were generally inversely correlated with growth rate. 5. From the inability of callus tissue and of cultured root apices to synthesize complex catechins, it is inferred that complex catechin formation in intact plants is associated with the process of cell vacuolation.

| S-EPMC1184766 | biostudies-other

5-Dehydroshikimate reductase in the tea plant (Camellia sinensis L.). Properties and distribution.

Project description:1. A method for the extraction of 5-dehydroshikimate reductase (EC 1.1.1.25) from tea plant tissues in an active soluble state has been developed. It is dependent on the use, in the extraction medium, of an insoluble polyphenol adsorbent (Polyclar AT), which prevents the polyphenols present from precipitating all the proteins. 2. The enzyme has the following properties: pH optima at pH10.1 in glycine-sodium hydroxide buffer and at pH7.7 in tris-hydrochloric acid buffer; K(m) (NADP) 32mum and K(m) (shikimate) 0.43mm; and NADP-specificity. It was completely inhibited by 0.33mm-p-chloromercuribenzoate and this inhibition was completely reversed by 10mm-cysteine. Iodoacetate and arsenite inhibited the enzyme to a smaller extent. 3. The specific activity of the enzyme was higher in the parts of the actively growing shoot tips (third leaf>stem>second leaf>first leaf>bud) than in the mature leaves. However, the mature leaves had the greatest total activity. 4. The importance of these findings with respect to flavanol biosynthesis in tea plants is discussed.

| S-EPMC1264822 | biostudies-other

an evergrowing tea (Camellia sinensis L.) cultivar

Project description:Tea (Camellia sinensis (L.) O. Kuntze) is an important non-alcoholic commercial beverage crop. Tea tree is a perennial plant, and winter dormancy is its part of biological adaptation to environmental changes. We recently discovered a novel tea tree cultivar that can generate tender shoots in winter, but the regulatory mechanism of this ever-growing tender shoot development in winter is not clear. In this study, we conducted a proteomic analysis for identification of key genes and proteins differentially expressed between the winter and spring tender shoots, to explore the putative regulatory mechanisms and physiological basis of its ever-growing character during winter.

2022-02-23 | PXD008958 | Pride

Green tea (Camellia sinensis) attenuates nephropathy by downregulating Nox4 NADPH oxidase in diabetic spontaneously hypertensive rats.

Project description:Green tea (GT), through its antioxidant properties, may be useful to treat or prevent human diseases. Because several lines of evidence suggest that oxidative stress contributes to the pathogenesis of diabetic nephropathy, we tested the hypothesis that GT prevents diabetes and hypertension-related renal oxidative stress, attenuating renal injury. Spontaneously hypertensive rats (SHR) with streptozotocin-induced diabetes and nondiabetic SHR were treated daily with tap water or freshly prepared GT (13.3 g/L). After 12 wk, the systolic blood pressure did not differ between treated and untreated nondiabetic or diabetic rats. However, body weight was less (P < 0.05) and glycemia was greater in diabetic SHR rats than in nondiabetic rats. Renal oxidative stress variables such as 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nitrotyrosine expression, NADPH oxidase-dependent superoxide generation, and the expression of renal cortex Nox4 were greater (P < 0.05) in diabetic rats that received water (DW) than in nondiabetic rats that received water (CW). The 8-OHdG and NADPH oxidase-dependent superoxide generation were significantly less in rats treated with GT. Nitrotyrosine and Nox4 expression were significantly less in diabetic rats that received GT (DGT) than in DW. Likewise, the indices of renal injury, albuminuria, and renal expression of collagen IV were significantly greater in DW than in CW. These differences were significantly less in DGT than in DW. GT reestablished the redox state and reduced the indicators of nephropathy without altering glycemia and blood pressure levels in diabetic SHR. These findings suggest that the consumption of GT may ameliorate nephropathy in diabetic hypertensive patients.

| S-EPMC2714376 | biostudies-literature

The distribution of polyphenols in the tea plant (Camellia sinensis L.).

Project description:1. Methods for the separation and determination of the polyphenolic components of the tea plant by thin-layer chromatography and colorimetric reactions have been devised. 2. High concentrations of catechins, flavonols and depsides were found to be restricted to the young vegetative and floral shoots, whereas leucoanthocyanins or flavylogens were characteristic of the more bulky axial tissues of the plant. 3. In the young shoots cell growth was correlated with an increasing degree of flavonoid B-ring hydroxylation. 4. Maximal flavylogen concentrations occurred in the outer protective layers of stem and of seed coat. 5. Mature leaves were shown to contain derivatives of the flavones apigenin and luteolin. 6. Developing seedlings showed a steady increase in polyphenol complexity; flavylogens were concentrated at shoot and root apices and accumulated at the stem base. 7. It is postulated that the flavanols (leucoanthocyanins and catechins), because they can co-polymerize, are of use to the plant for protection of wood and bark against infection and decay.

| S-EPMC1184764 | biostudies-other

Metabolite signatures of diverse Camellia sinensis tea populations.

Project description:The tea plant (Camellia sinensis) presents an excellent system to study evolution and diversification of the numerous classes, types and variable contents of specialized metabolites. Here, we investigate the relationship among C. sinensis phylogenetic groups and specialized metabolites using transcriptomic and metabolomic data on the fresh leaves collected from 136 representative tea accessions in China. We obtain 925,854 high-quality single-nucleotide polymorphisms (SNPs) enabling the refined grouping of the sampled tea accessions into five major clades. Untargeted metabolomic analyses detect 129 and 199 annotated metabolites that are differentially accumulated in different tea groups in positive and negative ionization modes, respectively. Each phylogenetic group contains signature metabolites. In particular, CSA tea accessions are featured with high accumulation of diverse classes of flavonoid compounds, such as flavanols, flavonol mono-/di-glycosides, proanthocyanidin dimers, and phenolic acids. Our results provide insights into the genetic and metabolite diversity and are useful for accelerated tea plant breeding.

| S-EPMC7642434 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data