Results 201 to 210 of about 19,118 (230)

Olive catechol oxidase ‐ changes during fruit development

Journal of the Science of Food and Agriculture, 1977
AbstractChanges were recorded in the subcellular location of catechol oxidase. In the green olive the enzyme is tightly bound to the chloroplast whereas in the black fruit it is essentially soluble. During fruit development, enzyme activity per fruit declines while the o‐diphenolic content rises steadily.
N, Ben-Shalom, V, Kahn, E, Harel, A M, Mayer   +3 more
openaire   +2 more sources

Catechol oxidases, endogenous substrates and browning in developing apples

Journal of the Science of Food and Agriculture, 1966
AbstractThe content of o‐diphenols and catechol oxidase activity was followed in developing apples from fruit set to harvest time. Afterwards their level drops, apparently due to conversion to other compounds and cessation of synthesis. Catechol oxidase activity shows a peak after that occurring in content of o‐diphenols.
E, Harel, A M, Mayer, Y, Shain
openaire   +2 more sources

Catechol oxidase of red delicious apple peel

Phytochemistry, 1972
Abstract Catechol oxidase has been solubilized from the particulate fraction of apple peel using Triton X-100, dialysis and butanol extraction. The partially purified enzyme retained activity during lyophilization in the presence of mercaptobenzothiazole. The substrate specificity and pH optima of the enzyme are reported.
David A. Stelzig, S. Akhtar, S. Ribeiro
openaire   +1 more source

Synthetic models of the active site of catechol oxidase: mechanistic studies

Chemical Society Reviews, 2006
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Koval, Iryna, Gamez, Patrick, Belle, Catherine, Selmeczi, Katalin, Reedijk, Jan   +4 more
openaire   +3 more sources

The selective inhibition of catechol oxidases by salicylhydroxamic acid.

Phytochemistry, 1988
Abstract Salicylhydroxamic acid (SHAM) has been shown to be a powerful and selective inhibitor of catechol oxidases but was without effect on laccases.
Andrew C. Allan, John R.L. Walker
openaire   +1 more source

Assay of catechol oxidase—a critical comparison of methods

Phytochemistry, 1966
Abstract Manometric, polarographic, chronometric and spectrophotometric methods for the determination of catechol oxidase activity were critically compared. Where possible, product formation, disappearance of substrate and ratios between oxygen uptake and substrate disappearance were determined.
A.M. Mayer, E. Harel, R. Ben-Shaul
openaire   +1 more source

Partial purification and properties of catechol oxidases in grapes

Phytochemistry, 1971
Abstract Grapes contain a high level of catechol oxidase activity. The enzyme is located in a particulate fraction of the cell, apparently in the plastids. It resembles catechol oxidases from other fruits in many aspects but differs in its relatively high activity towards caffeic and p-hydroxycinnamic acids and in its high affinity towards the latter.
E. Harel, A.M. Mayer
openaire   +1 more source

Phenylhydrazine, a specific irreversible inhibitor of catechol oxidase

Phytochemistry, 1971
Abstract Phenylhydrazine is shown to specifically inhibit a number of catechol oxidases from plant tissues. A laccase-like enzyme from peaches is not inhibited while ascorbic oxidase is only partly inhibited by relatively high concentrations of the inhibitor.
H.R. Lerner, E. Harel, E. Lehman, A.M. Mayer   +3 more
openaire   +1 more source

Limitations of the quantitative cytochemical assay of catechol oxidase in melanoma cells

The Histochemical Journal, 1988
The cytochemical quantification of catechol oxidase activity in fixed B16 melanoma cells was investigated using dopa as the substrate. Inhibitors showed that peroxidases do not significantly interfere. The kinetics of melanin formation were studied initially in solution with purified catechol oxidase.
A C, Croce, G, Bottiroli, E, Prosperi, R, Supino, P J, Stoward   +4 more
openaire   +2 more sources

Crystal structure of a plant catechol oxidase containing a dicopper center

Nature Structural Biology, 1998
Catechol oxidases are ubiquitous plant enzymes containing a dinuclear copper center. In the wound-response mechanism of the plant they catalyze the oxidation of a broad range of ortho-diphenols to the corresponding o-quinones coupled with the reduction of oxygen to water. The crystal structures of the enzyme from sweet potato in the resting dicupric Cu(
T, Klabunde, C, Eicken, J C, Sacchettini, B, Krebs   +3 more
openaire   +2 more sources