62 research outputs found
New insights into the dynamics of the glutathione-ascorbate redox system of plants
The Hallilwell-Asada-Foyer redox cascade (HAF) is viewed as a H2O2 detoxifying system with a great variety of responses against environmental changes. The functional consequences of these responses are interpreted intuitively because a systemic analysis of the inherent dynamic potential of the HAF is lacking. With the help of numerical modelling we show that in wheat roots parameter patterns are established which result in homeostatic states of HAF over a vast range of environmental changes. The reduced fractions glutathione (GSH) and ascorbate (ASC) remain on high levels even during dramatic changes in the enzyme activity ratios of glutathione reductase, dehydroascorbate reductase and ascorbat peroxidase. Necessarily their oxidised counterparts dithioglutathione (GSSG) and dehydroascorbate (DHA) stay in these buffered regions on very low concentration levels. Our modelling shows that redox ratios GSH/GSSG and ASC/DHA can be modified additionally via changes in NADPH/H2O2 ratios. Thus, the redox states of GSH and ASC can not simply be regarded as indicators for oxidative stress with respect to H2O2 levels. The involvement of the redox variables in other redox processes than the HAF reaction (redox proteome) and / or their utilisation in metabolism (protein modification, detoxification of xenobiotics) are viewed to cause system relaxations of the redox variables. The re-establishment of their homeostatic ratios follow time courses which are redox moiety specific and are balanced according to the existing parameter patterns. Despite of its detoxification function the HAF balances the glutathione / ascorbate redox state in cells according to the prevailing physiological conditions
Analysis of arginine and lysine methylation utilizing peptide separations at neutral pH and electron transfer dissociation mass spectrometry
Functional insights from structures of coactivator-associated arginine methyltransferase 1 domains
On the mechanism of inhibition of mitochondrial glutamate-oxalacetate-transaminase in SO2-fumigated peas
Inhibition and regeneration of rat liver enzymes hydrolyzing acetanilide ando-Nitrophenyl butyrate
On the mechanism of action of glutamate dehydrogenase from pea seedlings and the regulation of the activity by adenosine phosphates, the energy charge and ions
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