Unexpected Dose Response of Copper Concentration on Lipoprotein Oxidation in Serum: Discovery of A Unique Peroxidase-Like Activity of Urate/Albumin in the Presence of High Copper Concentrations

1997 ◽  
Vol 23 (5) ◽  
pp. 699-705 ◽  
Author(s):  
Julie M Proudfoot ◽  
Ian B Puddey ◽  
Lawrie J Beilin ◽  
Roland Stocker ◽  
Kevin D Croft
Keyword(s):  
Dose Response ◽  
Copper Concentration ◽  
Lipoprotein Oxidation ◽  
High Copper

A Third Millennium B.C. Glazed Quartz Bead From Tell Es-Sweyhat, Syria

1992 ◽  
Vol 267 ◽  
Author(s):  
Pamela B. Vandiver ◽  
Mark Fenn ◽  
T.A. Holland
Keyword(s):  
Copper Oxide ◽  
Copper Concentration ◽  
Oxide Content ◽  
Sample Handling ◽  
The Third ◽  
Poor State ◽  
The Poor ◽  
High Copper ◽  
Dead End ◽  
Third Millennium

ABSTRACTThe probable composition of a weathered, blue-green glaze on a ground quartz bead was reconstructed. The bead was excavated from Operation 5 at Tell es-Sweyhat, Syria, in 1991 and is dated to the last quarter of the third millennium B.C. Special sample handling was required by the poor state of preservation of the glaze. Microprobe analyses and replicate melts showed that the composition was 60% SiO2, 20% CuO and 20% flux, probably as soda, potassia or a combination. This composition is unusual for ancient glasses and glazes because of its high copper oxide content, which may indicate a link with copper or malachite technology. Very few glass and glaze compositions are known from the third millennium B.C., and none of these has such a high copper concentration, nor are there examples reported from the mid-second millennium B.C. with one exception of glazed tiles from Kerma in Sudan. This rare and unusual composition suggests that there may have been several paths to the development of glasses and glazes. Some of these paths were successful, and some others, as this one, did not continue and were “dead-end” technologies.

Berberine Production by CulturedCoptis japonicaCells in a One-stage Culture Using Medium with a High Copper Concentration

1988 ◽  
Vol 52 (7) ◽  
pp. 1835-1836
Author(s):  
Teijiro Morimoto ◽  
Yasuhiro Hara ◽  
Yukimi Kato ◽  
Junzo Hiratsuka ◽  
Toshihiro Yoshioka ◽  
...  
Keyword(s):  
Copper Concentration ◽  
One Stage ◽  
High Copper

scholarly journals Saccharomyces cerevisiae Concentrates Subtoxic Copper onto Cell Wall from Solid Media Containing Reducing Sugars as Carbon Source

2021 ◽  
Vol 8 (3) ◽  
pp. 36
Author(s):  
Lavinia L. Ruta ◽  
Ileana C. Farcasanu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Carbon Source ◽  
Copper Concentration ◽  
Reducing Sugars ◽  
Carbon Sources ◽  
Wine Production ◽  
Physiological Limits ◽  
High Copper ◽  
Cell Wall Disruption

Copper is essential for life, but it can be deleterious in concentrations that surpass the physiological limits. Copper pollution is related to widespread human activities, such as viticulture and wine production. To unravel aspects of how organisms cope with copper insults, we used Saccharomyces cerevisiae as a model for adaptation to high but subtoxic concentrations of copper. We found that S. cerevisiae cells could tolerate high copper concentration by forming deposits on the cell wall and that the copper-containing deposits accumulated predominantly when cells were grown statically on media prepared with reducing sugars (glucose, galactose) as sole carbon source, but not on media containing nonreducing carbon sources, such as glycerol or lactate. Exposing cells to copper in liquid media under strong agitation prevented the formation of copper-containing deposits at the cell wall. Disruption of low-affinity copper intake through the plasma membrane increased the potential of the cell to form copper deposits on the cell surface. These results imply that biotechnology problems caused by high copper concentration can be tackled by selecting yeast strains and conditions to allow the removal of excess copper from various contaminated sites in the forms of solid deposits which do not penetrate the cell.

A comparison of the kinetics of low-density lipoprotein oxidation induced by copper or by γ-rays: Influence of radiation dose-rate and copper concentration

2001 ◽  
Vol 79 (2) ◽  
pp. 114-121
Author(s):  
Abdelouahed Khalil ◽  
Tamàs Fülöp
Keyword(s):  
Dose Rate ◽  
Copper Concentration ◽  
Copper Ions ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Oxidation ◽  
Radiation Dose Rate ◽  
Γ Rays ◽  
Kinetics Of

The oxidation of low-density lipoproteins is the first step in the complex process leading to atherosclerosis. The aim of our study was to compare the kinetics of low density lipoprotein oxidation induced by copper ions or by oxygen free radicals generated by60Co γ-rays. The effects of copper concentration and irradiation dose-rate on LDL peroxidation kinetics were also studied. The oxidation of LDL was followed by the measurement of conjugated diene, hydroperoxides, and thiobarbituric acid reactive substance formation as well as α-tocopherol disappearance. In the case of gamma irradiation, the lag-phase before the onset of lipid peroxidation was inversely correlated to the radiation dose-rate. The radiation chemical rates (v) increased with increasing dose-rate. Copper-induced LDL peroxidation followed two kinetic patterns: a slow kinetic for copper concentrations between 5–20 µM, and a fast kinetic for a copper concentration of 40 µM. The concentration-dependent oxidation kinetics suggest the existence of a saturable copper binding site on apo-B. When compared with γ-rays, copper ions act as drastic and powerful oxidants only at higher concentrations ([Formula: see text]40 µM).Key words: LDL, peroxidation, kinetics, copper, γ-radiolysis, dose-rate.

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