Purification of a polyphenol oxidase isoform from potato (Solanum tuberosum) tubers

Marri, Costanza; Frazzoli, Alessandra; Hochkoeppler, Alejandro; Poggi, Valeria

doi:10.1016/s0031-9422(03)00353-4

Cited by 39 publications

(26 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although it is the first time this trait is analyzed by means of QTL analysis and a candidate gene approach, extensive research has been performed on the trait focussing on both the enzymatic components (Hunt et al 1993; Newman et al 1993; Thygesen et al 1995) and substrate components (Corsini et al 1992; Marri et al 2003; Mondy and Munshi 1993). The enzymatic component is represented by the enzyme PPO.…”

Section: Discussionmentioning

confidence: 99%

Unravelling enzymatic discoloration in potato through a combined approach of candidate genes, QTL, and expression analysis

et al. 2007

View full text Add to dashboard Cite

Enzymatic discoloration (ED) of potato tubers was investigated in an attempt to unravel the underlying genetic factors. Both enzyme and substrate concentration have been reported to inXuence the degree of discoloration and as such this trait can be regarded as polygenic. The diploid mapping population C £ E, consisting of 249 individuals, was assayed for the degree of ED and levels of chlorogenic acid and tyrosine. Using this data, Quantitative Trait Locus (QTL) analysis was performed. Three QTLs for ED have been found on parental chromosomes C3, C8, E1, and E8. For chlorogenic acid a QTL has been identiWed on C2 and for tyrosine levels, a QTL has been detected on C8. None of the QTLs overlap, indicating the absence of genetic correlations between these components underlying ED, in contrast to earlier reports in literature. An obvious candidate gene for the QTL for ED on Chromosome 8 is polyphenol oxidase (PPO), which was previously mapped on chromosome 8. With gene-speciWc primers for PPO gene POT32 a CAPS marker was developed. Three diVerent alleles (POT32-1, -2, and -3) could be discriminated. The segregating POT32 alleles were used to map the POT32 CAPS marker and QTL analysis was redone, showing that POT32 coincides with the QTL peak. A clear correlation between allele combinations and degree of discoloration was observed. In addition, analysis of POT32 gene expression in a subset of genotypes indicated a correlation between the level of gene expression and allele composition. On average, genotypes having two copies of allele 1 had both the highest degree of discoloration as well as the highest level of POT32 gene expression.

show abstract

Section: Discussionmentioning

confidence: 99%

Unravelling enzymatic discoloration in potato through a combined approach of candidate genes, QTL, and expression analysis

et al. 2007

View full text Add to dashboard Cite

show abstract

“…This protein is responsible for the enzymatic browning reaction that occurs when tissues are damaged during the handling, storage and processing of fresh fruits and vegetables, as well as some animal products. [1,2] Browning reactions are made up of the following five basic types; ascorbic acid oxidation, [3] caramelization, [4] the enzymatic reactions of phenols, [5] the chemical reaction of amino groups (Maillard reaction) [6] and the oxidation of lipids to create browned polymers. [7] The oxidation of phenolic compounds to unstable o-quinones is known as "enzymatic browning".…”

Section: Introductionmentioning

confidence: 99%

Purification and Characterization of Polyphenol Oxidase from Hemşin Apple (Malus communisL.)

Aydin

Gülçın

Alwasel

2015

International Journal of Food Properties

View full text Add to dashboard Cite

The polyphenol oxidase (PPO) enzyme was purified and characterized from Hemşin Apple (Malus communis L.), which was organically grown in Hemşin, in the Rize province of Turkey. Enzyme (PPO) activation was determined with catechol substrate. Apples were homogenized with homogenate buffer (pH 8.5). This process was followed by precipitation with (20-80%) saturated solid (NH 4 ) 2 SO 4 and dialysis. Finally, purification with DE52-Cellulose ion-exchange and Sephadex G-25 columns was performed. Experiments were performed at an optimum pH (5.5) and optimum temperature (30-40°C). The kinetic and thermal parameters Km (3.40 mM), Vmax (333.3 EU/mL.min), Ea (3.57 kcal), ΔH (2.968 kcal/mol), Q 10 (1.33), k cat (24.57 min −1 ) and V 0 (7.2x10 3 mM −1 .min −1 ) were assessed. Additionally, the effects of Mg 2+ , Pb 2+ , Fe 2+ , Fe 3+ , Cd 2+ , Cu 2+ , Zn 2+ , Co 2+ , Al 3+ , Mn 2+ and Na + on enzyme activity was recorded, and the IC 50 values, K İ values and inhibition types were determined.

show abstract

“…In vitro activation of the latent enzyme can be accomplished by addition of SDS or proteolysis to remove the C-terminal domain [17]–[19]. Although some PPOs function as monomers [16], there are reports of multimeric forms that show enzymatic cooperativity [10], [14], [20], [21]–[22]. Two plant PPO structures have been solved by crystallography so far, and both structures comprise the tyrosinase domain only [23]–[24].…”

Section: Introductionmentioning

confidence: 99%

Structural Diversity in the Dandelion (Taraxacum officinale) Polyphenol Oxidase Family Results in Different Responses to Model Substrates

et al. 2014

View full text Add to dashboard Cite

Polyphenol oxidases (PPOs) are ubiquitous type-3 copper enzymes that catalyze the oxygen-dependent conversion of o-diphenols to the corresponding quinones. In most plants, PPOs are present as multiple isoenzymes that probably serve distinct functions, although the precise relationship between sequence, structure and function has not been addressed in detail. We therefore compared the characteristics and activities of recombinant dandelion PPOs to gain insight into the structure–function relationships within the plant PPO family. Phylogenetic analysis resolved the 11 isoenzymes of dandelion into two evolutionary groups. More detailed in silico and in vitro analyses of four representative PPOs covering both phylogenetic groups were performed. Molecular modeling and docking predicted differences in enzyme-substrate interactions, providing a structure-based explanation for grouping. One amino acid side chain positioned at the entrance to the active site (position HB2+1) potentially acts as a “selector” for substrate binding. In vitro activity measurements with the recombinant, purified enzymes also revealed group-specific differences in kinetic parameters when the selected PPOs were presented with five model substrates. The combination of our enzyme kinetic measurements and the in silico docking studies therefore indicate that the physiological functions of individual PPOs might be defined by their specific interactions with different natural substrates.

show abstract

Purification of a polyphenol oxidase isoform from potato (Solanum tuberosum) tubers

Cited by 39 publications

References 23 publications

Unravelling enzymatic discoloration in potato through a combined approach of candidate genes, QTL, and expression analysis

Unravelling enzymatic discoloration in potato through a combined approach of candidate genes, QTL, and expression analysis

Purification and Characterization of Polyphenol Oxidase from Hemşin Apple (Malus communisL.)

Structural Diversity in the Dandelion (Taraxacum officinale) Polyphenol Oxidase Family Results in Different Responses to Model Substrates

Contact Info

Product

Resources

About