Laccases, EC 1.10.3.2 or p-diphenol:dioxygen oxidoreductases, are multi-copper containing glycoproteins. Despite many years of research, genetic evidence for the roles of laccases in plants is mostly lacking. In this study, a reverse genetics approach was taken to identify T-DNA insertional mutants (the SALK collection) available for genes in the Arabidopsis laccase family. Twenty true null mut...

Cytochrome Oxidases, Gerald Babcock, Michigan State University, USA: Chair Robert Gennis, University of Illinois, USA: Structure and function of the heine-copper oxidases Ninian Blackburn, Oregon Graduate Institute, USA: XAS studies on heine-copper oxidases and models Stuart Ferguson, Oxford University, United Kingdom: Structure of Cytochrome cdl: An Oxidase and a Nitrite Reductase with an Unus...

In 1937, Stotz, Harrer, and King (1) reported that the activity of several plant juices in catalyzing the aerobic oxidation of ascorbic acid was dependent on their copper content, and such activity was lost upon treatment with substances known to form stable complexes with copper. Since that time, two basically different views have developed concerning the r&e of copper in the aerobic oxidation...

Processing and stabilising onion wastes (residues and surpluses of onion) could solve the environmental problem derived from a great onion wastes disposal. Moreover, obtaining stabilised onion by-products as natural antioxidant food ingredients could be advantageous to food industry, not only to improve the use of onion wastes but also to obtain new natural and functional ingredients. The aim o...

The more recent reports on polyphenol oxidase in plants and fungi are reviewed. The main aspects considered are the structure, distribution, location and properties of polyphenol oxidase (PPO) as well as newly discovered inhibitors of the enzyme. Particular stress is given to the possible function of the enzyme. The cloning and characterization of a large number of PPOs is surveyed. Although th...

The activities of catalase, peroxidase, and polyphenoloxidase were studied in attached and detached rice (Oryza sativa L. cv. Ratna) leaves. Catalase activity decreased while peroxidase and polyphenoloxidase activities increased during senescence of both attached and detached rice leaves. Kinetic (5 mum) and benzimidazole (1 mm), which are known to delay the senescence of detached rice leaves, ...

Type I IFN signaling is a central pathway that provides critical innate protection from viral and bacterial infection and can have regulatory outcomes in inflammatory settings. We determined previously that OPCs contained in the dietary supplement APP enhanced responses to type I IFN in vitro. Here, we confirm that OPCs from two different sources significantly increased pSTAT1, whereas a monome...

Catechol chemistry is used as a crosslinking tool abundantly in both natural organisms (e.g. mussels, sandcastle worms) and synthetic systems to achieve the desired mechanical properties. Despite this abundance and success, the crosslinking chemistry is still poorly understood. In this study, to simplify the system, yet to capture the essential chemistry, model compounds 4-methyl catechol and p...

It has been previously shown that many types of drugs alter the rate of metabolism of the catecholamine hormones (Axelrod and Laroche, 1959; Axelrod and Tomchick, 1959; Axelrod, 1960). The psychotropic drugs reserpine, chlorpromazine and imipramine speed the metabolism of epinephrine and norepinephrine, while the catechol-O-methyl transferase inhibitors, pyrogdlol and quercetin, block the metab...

The ability of 19 structural analogs of propyl gallate to inhibit purified soybean seed (Glycine max [L.] Merr. var. Ransom) lipoxygenase-2 (EC 1.13.11.12) was determined. The results indicate that the o-dihydroxy and not the ester function of propyl gallate is essential for inhibition of lipoxygenase. Catechol thus represents the minimum inhibitory structure. Among those compounds possessing a...