Permeability of fresh and stored human erythrocytes to glycerol and its acylated derivatives

Summary The effect of copper ions on the permeation of glycerol and its mono-, di-, and triacetate derivatives was studied in fresh and stored erythrocytes. Permeability was unchanged with storage. Acylated glycerols permeate the cells mainly by non-facilitated mechanism, as their transport is almost unaffected by copper ions.Portions of this work were included in the graduate thesis of Dr. Yaeger in partial fulfillment of the requirements for the M. D. degree.Acknowledgement. We thank Mrs Dalia Mazor for expert technical assistance.     

Release of pre-absorbed cadmium from cultured cells by the addition of copper ion

Summary The biological interaction between cadmium and copper has been studied. Cadmium uptake of KB cells was specifically inhibited by the addition of copper ions to the culture medium. Cadmium which had already been taken up by the cells was released following the addition of copper ions.The authors are grateful to Dr. M. Ishizawa for his helpful discussion.     

Cellular copper distribution: a mechanistic systems biology approach

Copper is an essential but potentially harmful trace element required in many enzymatic processes involving redox chemistry. Cellular copper homeostasis in mammals is predominantly maintained by regulating copper transport through the copper import CTR proteins and the copper exporters ATP7A and ATP7B. Once copper is imported into the cell, several pathways involving a number of copper proteins are responsible for trafficking it specifically where it is required for cellular life, thus avoiding the release of harmful free copper ions. In this study we review recent progress made in understanding the molecular mechanisms of copper transport in cells by analyzing structural features of copper proteins, their mode of interaction, and their thermodynamic and kinetic parameters, thus contributing to systems biology of copper within the cell.     

Endogenous copper is cytotoxic to a lymphoma in primary culture which requires thiols for growth

With the use of bathocuproine sulfonate, a copper-specific chelator as an indicator, we have demonstrated that copper ions, present as a natural medium constituent are toxic to the growth of a lymphoma in primary culture and are principally responsible for the growth requirement of mercaptoethanol and other thiols. By chelating trace copper normally present in the medium, bathocuproine sulfonate retarded the oxidation of cysteine to poorly utilized cystine, thus permitting its direct utilization by the cells for growth.     

Endogenous copper is cytotoxic to a lymphoma in primary culture which requires thiols for growth

Summary With the use of bathocuproine sulfonate, a copper-specific chelator as an indicator, we have demonstrated that copper ions, present as a natural medium constituent are toxic to the growth of a lymphoma in primary culture and are principally responsible for the growth requirement of mercaptoethanol and other thiols. By chelating trace copper normally present in the medium, bathocuproine sulfonate retarded the oxidation of cysteine to poorly utilized cystine, thus permitting its direct utilization by the cells for growth.     

Trace metal requirements in total parenteral nutrition: A theoretical approach by mathematical modeling

Summary A new computer-based approach has been developed to assess the optimal doses of essential trace metal ions which should be included in nutritive mixtures, used in human total parenteral nutrition, to compensate for the ligand-induced losses of these metal ions. An example of application is given for zinc, copper and manganese.     

Strukturspezifischer oxydativer abbau von peptid-metall-komplexen

Summary The decapeptide polymxine B can be split into sub-units by hydrogen peroxide or by UV-irradiation when complexed with copper(II) or nickel(II); the splitting points are probably related to the points of attachment of the metal ions.     

Biophysikalische Studien mit synthetischem Lezithin

Summary Synthetic lecithin, dissolved in chloroform, is able to add salts which are non-soluble in chloroform and to transfer these at neutral pH from the aqueous into the lipoid phase. The effect is dependent on the cation concentrations and particularly on their valency. Calcium, barium, copper ions, etc., are about one hundred times more effective than sodium and potassium. Two-basic amines are also very effective. For experimental reasons, anion was, up to now, not varied and in all tests tropeoline was used.      

Prokaryote-eukaryote interactions in trace element metabolism.Desulfovibrio sp. inHelix aspersa

Summary Snails (Helix aspersa) contain sulphate-reducing bacteria in their crops. Feeding such animals on food containing sulphate and molybdate ions does not induce a copper deficiency and in fact the bacteria appear to facilitate metal absorption. This is in contrast to the effects of these bacteria in ruminant cattle.     

Semen copper in normal and infertile subjects.

Concentration of copper in seminal plasma was found to be less than that of normal in cases of oligospermia and azoospermia. It was more in oligoasthenospermia and asthenospermia when compared with that of normal. Chances of initiation of sperm motility by copper is discussed alongwith the inhibitory role it plays.     

Structure and function of type I copper in multicopper oxidases

The type I copper center in multicopper oxidases is constructed from 1Cys2His and weakly coordinating 1Met or the non-coordinating 1Phe/1Leu, and it exhibits spectral properties and an alkaline transition similar to those of the blue copper center in blue copper proteins. Since the type I copper center in multicopper oxidases is deeply buried inside the protein molecule, electron transfers to and from type I copper are performed through specific pathways: the hydrogen bond between an amino acid located at the substrate binding site and a His residue coordinating type I copper, and the His-Cys-His sequence connecting the type I copper center and the trinuclear copper center comprised of a type II copper and a pair of type III coppers. The intramolecular electron transfer rates can be tuned by mutating the fourth ligand of type I copper. Further, mutation at the Cys ligand gives a vacant type I copper center and traps the reaction intermediate during the four-electron reduction of dioxygen.     

Cadmium-induced lipofuscins and effect of zinc on hepatopancreas cells inIdotea baltica

Histological investigation revealed cadmium-induced lipofuscin formation in hepatopancreatic cells of the crustacean isopod,Idotea baltica. A comparison of lipofuscin induction by cadmium and by copper showed that cadmium has a weaker peroxidative action than copper. The effect of cadmium was reduced by the simultaneous presence of zinc, which on its own was ineffective in lipofuscin induction. A tentative explantation of the interactive effects of these materials is suggested.     

Über das Cu2+-Bindungsvermögen einiger Aminosäuren und Peptide Metallionen und biologische Wirkung

Summary The capacity of binding copper ions of several aminoacids and peptides has been investigated. A direct colorimetric method measuring comparable values of bound Cu²⁺ has been developed.

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37. Mitteilung; 36. Mitteilung:R. Gall undH. Erlenmeyer, Helv. chim. Acta38, 1421 (1955).     

Antioxidant and prooxidant roles of copper in Tween 20-induced hemolysis of hamster and pig erythrocytes containing marginal vitamin E

The concentration-dependent effects of copper acting either as an antioxidant or as a prooxidant were examined in vitro using Tween 20-induced hemolysis. When cupric ion concentration was more than 10 M, free copper(II) acted as a prooxidant; both extensive hemolysis and production of unknown thiobarbituric acid-reactive substance occurred in hamster and pig erythrocytes irrespective of vitamin E status. However, when cupric ion concentration was 2–4 M in the incubation medium, copper showed a clear antioxidant activity, reducing both hemolysis and malondialdehyde production induced either by diluted peroxide-containing Tween 20 with ascorbic acid and sodium azide in vitamin E-deficient hamster erythrocytes, or by peroxide-containing Tween 20 in pig erythrocytes containing marginal amounts of vitamin E. Copper(II) is taken up by the erythrocytes, where copper(I)-complexes may contribute to the protection of cells with membrane vitamin E against oxidative radical attack.     

Semen copper in normal and infertile subjects

Summary Concentration of copper in seminal plasma was found to be less than that of normal in cases of oligospermia and azoospermia. It was more in oligoasthenospermia and asthenospermia when compared with that normal. Chances of initiation of sperm motility by copper is discussed alongwith the inhibitory role it plays.Acknowledgment. Authors are thankful to Dr. A. R. N. Setalwad, Assistant Professor in Preventive and Social Medicine for the statistical analysis of the study he did.     

Biologische und chemische Wege zur Anreicherung von Spurenelementen

Summary Using as examples hemovanadin, the vanadium-containing blood pigment of the ascidianPhallusia mamillata, and ferritin, the protein for iron storage in mammals, pathways for the concentration of vanadium and of iron are described: These have been realizedin vitro and may occurin vivo. The uptake and concentration of heavy metals in nature seems to occur by means of complexing agents.High molecular weight, insoluble chelating substances which are able to bind metal ions, especially uranium and copper selectively, have been synthesized. Recovery of the metals is possible without destruction of the chelating groups, and, as in the case of ion-exchange resins, repeated cycles can be carried out without diminishing the metal-binding capacity.     

Function and molecular evolution of multicopper blue proteins

Multicopper blue proteins (MCBPs) are multidomain proteins that utilize the distinctive redox ability of copper ions. There are a variety of MCBPs that have been roughly classified into three different groups, based on their domain organization and functions: (i) nitrite reductase-type with two domains, (ii) laccase-type with three domains, and (iii) ceruloplasmin-type with six domains. Together, the second and third group are often commonly called multicopper oxidases (MCOs). The rapid accumulation of genome sequence information in recent years has revealed several new types of proteins containing MCBP domains, mainly from bacteria. In this review, the recent research on the functions and structures of MCBPs is summarized, mainly focusing on the new types. The latter half of this review focusses on the twodomain MCBPs, which we propose as the evolutionary intermediate of the MCBP family.Received 25 February 2005; received after revision 23 May 2005; accepted 31 May 2005     

Tetanus toxin does not affect the release of noradrenaline and taurine from rat cerebral cortex slices evoked by high K+ and Na+-free media

Summary Noradrenaline and taurine release from superfused rat cerebral cortex slices was stimulated by potassium ions, veratrine, ouabain and omission of sodium ions. Tetanus toxin enhanced only the ouabain-evoked calcium-dependent noradrenaline release and the ouabain-evoked calcium-independent taurine release. The uptake of both was marginally affected.     

The pre-history of hemocyanin. The discovery of copper in the blood of molluscs

The presence of copper in molluscs was discovered in 1833 by Bartolomeo Bizio, a Venetian chemist, who found copper in marine gastropods of the family Muricidae during his studies on the purple dye he had isolated from these animals. Bizio was so surprised by this finding that he extended his analysis to several other invertebrate species in which he identified the metal.     

Tetanus toxin does not affect the release of noradrenaline and taurine from rat cerebral cortex slices evoked by high K+ and Na+-free media

Noradrenaline and taurine release from superfused rat cerebral cortex slices was stimulated by potassium ions, veratrine, ouabain and omission of sodium ions. Tetanus toxin enhanced only the ouabain-evoked calcium-dependent noradrenaline release and the ouabain-evoked calcium-independent taurine release. The uptake of both was marginally affected.