Electron paramagnetic resonance studies of cobalt-copper bovine superoxide dismutase.

Abstract 1. EPR spectra of cobalt-copper bovine superoxide dismutase at liquid nitrogen and liquid helium temperature show that the two metal centers are magnetically coupled. The temperature dependence of the spectra indicates that this coupling arises from an exchange interaction. 2. The EPR spectrum of the Co(II) of the enzyme can only be seen after reduction of the Cu(II), at very low temperature. It is typical of tetrahedral coordination which is distorted in a particular way. The EPR parameters are g⊥ ≃ 4, g|| ≃ 2, D = 11.5 cm-1. No feature indicating interaction between the two Co(II) centers is observed. 3. Anions such as CN- and N3- do not affect the EPR spectrum of Co(II) significantly, but only modify the spectrum of Cu(II). It is concluded that the Co(II) site (and presumably the native Zn(II) site) can be described as distorted tetrahedral, strongly spin-coupled to the Cu(II) and therefore very near to it, and noninteracting with the other Co(II) site and with solvent molecules

Kinetics of Electron Transfer between Azurin and Cytochrome 551 from Pseudomonas

Abstract The kinetics of electron transfer between the copper-containing protein azurin (Cu++/Cu+) and cytochrome 551 (Fe+++/Fe++) from Pseudomonas has been studied by rapid mixing methods. The reaction in both directions is fast; at low reagent concentrations (∼10-6 m) the apparent second order rate constant, at 20°, is about 3 x 106 m-1 sec-1 for the reaction Fe++ + Cu++ and 1.4 x 106 m-1 sec-1 for the reaction Fe+++ + Cu+. At high reagent concentrations the rates tend to reach a limiting value indicating that the reaction is not a simple second order process. The kinetics of the reactions of the reduced and oxidized forms of azurin and Pseudomonas cytochrome 551 with ferricyanide and dithionite has also been investigated. The rates of these reactions, at comparable reagent concentrations, are orders of magnitude lower than that between azurin and cytochrome 551

Chromatographic Evidence on the Occurrence of Thiotaurine in the Urine of Rats Fed with Cystine

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Diets supplemented with condensed and hydrolysable tannins affected rumen fatty acid profile and plasmalogen lipids, ammonia and methane production in an in vitro study

The livestock sector constitutes 14.5% of global green-house gas (GHG) emissions and soil and water pollution due to nitrogen excretion. Methane and nitrogen excretions in ruminants can be mitigated by specific feeding strategies, and tannins reduce methanogenesis and ammonia syntheses. In our study, two kinds of condensed tannins (Mimosa and Gambier) and two kinds of hydrolysable tannins (Chestnut and Tara) were added (4 g/100 g DM) to a basal feed (barley: 48 g/100 g DM, wheat bran: 23 g/100 g DM, dehydrated alfalfa hay:15 g/100 g DM, soybean meal: 10 g/100 g DM and molasses: 2 g/100 g DM), inoculated with rumen fluid and fermented for 24 h. The methane, ammonia, fatty acid and plasmalogen lipid profile were determined. The results confirmed that tannins are an important family of heterogeneous compounds whose effect on rumen metabolism is strongly linked to their different characteristics. Chestnut tannin extract was shown to be a good compromise. It improved the sustainability of ruminant rearing by decreasing methanogenesis (control feed 0.159 vs chestnut feed 0.137 mmol/L rumen fluid; p =.0326), ammonia production (control feed 248 vs chestnut feed 179 mg/L rumen fluid; p <.0001) and enhancing acetate synthesis (production rate: chestnut 68.68% vs 49.64% of control).HIGHLIGHTS Tannin extracts from trees and shrubs can be used to modulate rumen fermentation. The positive effect of chestnut tannin extract was demonstrated on methane and ammonia production. Tannins showed no protective action on C18:2 trans 11

Experiments with D-cysteine in the rat.

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THE ISOLATION OF PURE HYPOTAURINE FROM THE URINE OF RATS FED CYSTINE

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UA28/1 The Personnel File

Newsletter created by Personnel Services to disseminate information to WKU faculty and staff. This issue has articles about tuition scholarships, payroll staff and A.F. Godby

Bioseparation of Four Proteins from Euphorbia characias Latex: Amine Oxidase, Peroxidase, Nucleotide Pyrophosphatase/Phosphodiesterase, and Purple Acid Phosphatase

This paper deals with the purification of four proteins from Euphorbia characias latex, a copper amine oxidase, a nucleotide pyrophosphatase/phosphodiesterase, a peroxidase, and a purple acid phosphatase. These proteins, very different in molecular weight, in primary structure, and in the catalyzed reaction, are purified using identical preliminary steps of purification and by chromatographic methods. In particular, the DEAE-cellulose chromatography is used as a useful purification step for all the four enzymes. The purification methods here reported allow to obtain a high purification of all the four proteins with a good yield. This paper will give some thorough suggestions for researchers busy in separation of macromolecules from different sources

The cultivation of Castanea sativa (Mill.) in Europe, from its origin to its diffusion on a continental scale

The history of Castanea sativa (sweet chestnut) cultivation since medieval times has been well described on the basis of the very rich documentation available. Far fewer attempts have been made to give a historical synthesis of the events that led to the cultivation of sweet chestnut in much earlier times. In this article we attempt to reconstruct this part of the European history of chestnut cultivation and its early diffusion by use of different sources of information, such as pollen studies, archaeology, history and literature. Using this multidisciplinary approach, we have tried to identify the roles of the Greek and Roman civilizations in the dissemination of chestnut cultivation on a European scale. In particular, we show that use of the chestnut for food was not the primary driving force behind the introduction of the tree into Europe by the Romans. Apart from the Insubrian Region in the north of the Italian peninsula, no other centre of chestnut cultivation existed in Europe during the Roman period. The Romans may have introduced the idea of systematically cultivating and using chestnut. In certain cases they introduced the species itself; however no evidence of systematic planting of chestnut exists. The greatest interest in the management of chestnut for fruit production most probably developed after the Roman period and can be associated with the socio-economic structures of medieval times. It was then that self-sufficient cultures based on the cultivation of chestnut as a source of subsistence were forme