ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effect of drugs on oxidation and precipitation of the isolated chains of human hemoglobin (1978)
    Springer
    Molecular and cellular biochemistry 19 (1978), S. 43-48 
    Details
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The paper deals with the action of: primaquine, epinephrine, adrenochrome, acetylphenylhydrazine and sulphanilamide on the autoxidation of the isolated chains from human hemoglobin and on the precipitation which follows. The effect of superoxide dismutase and catalase on the drug induced autoxidation allows the assessment of the possible role of 02 derivatives (notably superoxide or peroxide) in the overall reaction mechanism. It is also shown that primaquine and acetylphenylhydrazine enhance precipitation of the isolated oxidized chains, while epinephrine and adrenochrome display a small inhibitory effect on precipitation. These effects do not involve O2 radicals, but have presumably to be related to a destabilizing (or stabilizing) action of the drugs on the structure of the protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231233
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Purification of a fully metal-depleted Cu, Zn superoxide dismutase from copper-deficient rat liver (1997)
    Springer
    BioMetals 10 (1997), S. 257-262 
    Details
    ISSN: 1572-8773
    Keywords: copper-deficiency ; rat liver ; superoxide dismutase ; purification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A copper-deprived form of the enzyme Cu, Zn superoxide dismutase was identifiedin the liver of rats made copper-deficient by dietary restriction. In homogenates ofsuch livers Cu, Zn superoxide dismutase presents a dis-homogeneous electrophoreticprofile with respect to the native enzyme. When rat liver extracts were treated withexogenous copper an electrophoretic pattern resembling the native one was observed.Enzyme purified by chromatography on DE-52 resin shows two major components, onecorresponding to genuine, native enzyme and another one, eluting at higher ionicstrength. The latter protein (Fraction II) consists of several isoforms which showthe same characteristics of the native superoxide dismutase as far as immunoreactivityand molecular weight are concerned, but with decreased contents of copper and zinc. Itscatalytic constant, referring to copper content, was 15 times lower than that obtainedfor the native enzyme. Moreover, the catalytic power of purified Fraction II was notregained upon incubation with copper. The occurrence of a superoxide dismutase voidof metals confirms the hypothesis that this protein plays a dual physiological role:in metal metabolism and in superoxide anion dismutation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018364130807
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Copper-glutathione complexes under physiological conditions: structures in solution different from the solid state coordination (1996)
    Springer
    BioMetals 9 (1996), S. 3-9 
    Details
    ISSN: 1572-8773
    Keywords: copper complexes ; copper transport ; ESR spectroscopy ; glutathione
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The physiologically important copper complexes of oxidized glutathione have been examined by electron spin resonance (ESR) spectroscopy in aqueous solution at neutral pH. Low temperature measurements show that the Cu(II) binding site in oxidized glutathione has the same ligand arrangement as in the copper complexes of S-methylglutathione, glutamine, glutamate and glycine. The site is composed of the amino nitrogens and the carboxyl oxygens of two γ-glutamyl residues; there is no interaction with amide nitrogens, the sulphur bond or the glycyl carboxyl groups. At high metal to ligand ratios a binuclear species exists, in which each Cu(II) binds only to one γ-glutamyl residue. The previously reported forbidden transition detected at g = 4 is due to non-specific aggregation and not to spin coupling of intramolecular sites. Liquid solution ESR spectra show the Cu(II)-glutathione complex has a lower mobility than the corresponding Cu(II)-S'-methylglutathione species. From the degree of spectral anisotropy the complex with glutathione is calculated to exist as a dimer. These results demonstrate that the physiologically relevant complex between copper and oxidized glutathione in solution is completely different from the known solid state structure determined by crystallography.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188083
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A comparative study of bovine, porcine and yeast superoxide dismutases (1983)
    Springer
    Molecular and cellular biochemistry 51 (1983), S. 161-164 
    Details
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The Cu,Zn superoxide dismutases from bovine and porcine erythrocytes and from yeast have been investigated with the aim to identify structural differences in relation to possible functional variability in this highly homologous class of protein. The isoelectric points of the bovine, porcine and yeast proteins were found to be 4.8, 5.8 and 4.5 respectively. According to these values the net protein charge, as evaluated by gel electrophoresis, varied more significantly for the porcine protein than for the other two proteins tested. The catalytic constants were found to be higher at pH = 7.6 than at pH = 10.0 for all the three enzymes. This relative increase was much more pronounced in the case of the porcine enzyme. The KM value at pH = 10.0 was also significantly higher for the porcine enzyme. Since the spectroscopic properties of the active sites were identical for the three proteins, these results point to modulation effects by positively charged amino acid residues on the superoxide dismutase activity of these proteins, in a way that the resultant net charge of the protein seems to be as important as specific residues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Decrease of cytochrome c oxidase protein in heart mitochondria of copper-deficient rats (1998)
    Springer
    BioMetals 11 (1998), S. 207-212 
    Details
    ISSN: 1572-8773
    Keywords: copper deficiency ; Cytochrome c oxidase ; heart ; mitochondria ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Copper deficiency has been reported to be associated withdecreased cytochrome c oxidase activity, whichin turn may be responsible for theobserved mitochondrial impairment and cardiac failure. We isolatedmito-chondriafrom hearts of copper-deficient rats: cytochrome c oxidase activity was found to be lowerthan incopper-adequate mitochondria. The residual activity paralleled coppercontent of mitochondria and also corresponded with the heme amount associated with cytochromeaa3. In fact, lower absorption in thea-band region of cytochrome aa3 was foundfor copper-deficient rat heart mitochondria. Gel electrophoresisof protein extractedfrom mitochondrial membranes allowed measurements of protein content of thecomplexes ofoxidative phosphorylation, revealing a lower content of complex IV protein incopper-deficientrat heart mitochondria. The alterations caused by copper deficiency appear to bespecific forcytochrome c oxidase. Changes were not observed for F 0 F 1 ATP synthase activity,for heme contents ofcytochrome c and b, and for protein contents of complexes I, III and V.The present study demonstrates that the alteration of cytochrome c oxidase activityobserved in copper deficiency is due to a diminishedcontent of assembled protein and that shortnessof copper impairs heme insertion into cytochrome c oxidase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009274131473
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Copper uptake and intracellular distribution in the human intestinal Caco-2 cell line (2000)
    Springer
    BioMetals 13 (2000), S. 179-185 
    Details
    ISSN: 1572-8773
    Keywords: GSH ; heavy metals ; metallothionein ; passive uptake ; 64Cu
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The apical uptake of 64CuCl2 was investigated in human differentiated intestinal Caco-2 cells grown on permeable supports. At pH 6.0 in the apical compartment, the uptake of copper was linear over the first 6 min and between 10 and 80 μM CuCl2 exhibited non-saturable transport kinetics. In addition, copper uptake was energy-independent, affected by the valency state of copper, preferring Cu(II) over Cu(I), and not influenced by high (10 mM) extracellular calcium. The intracellular distribution of copper was investigated by FPLC at different times of uptake (`pulse') and of `chase'. Intracellular copper initially bound predominantly to low molecular weight components (i.e., glutathione), and subsequently shifted to higher molecular weight components such as metallothionein and Cu,Zn superoxide dismutase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009271622356
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Manganese accumulation in yeast cells (1989)
    Springer
    BioMetals 2 (1989), S. 6-10 
    Details
    ISSN: 1572-8773
    Keywords: Manganese ; Electron spin resonance ; Superoxide dismutase ; Saccharomyces cerevisiae ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Manganese accumulation was studied by room-temperature electron spin resonance (ESR) spectroscopy inSaccharomyces cerevisiae grown in the presence of increasing amounts of MnSO4. Mn2+ retention was nearly linear in intact cells for fractions related to both low-molecular-mass and macromolecular complexes (‘free’ and ‘bound’ Mn2+, respectively). A deviation from linearity was observed in cell extracts between the control value and 0.1 mM Mn2+, indicating more efficient accumulation at low Mn2+ concentrations. The difference in slopes between the two straight lines describing Mn2+ retention at concentrations lower and higher than 0.1 mM, respectively, was quite large for the free Mn2+ fraction. Furthermore it was unaffected by subsequent dialyses of the extracts, showing stable retention in the form of low-molecular-mass complexes. In contrast, the slope of the line describing retention of ‘bound’ Mn2+ at concentrations higher than 0.1 mM became less steep after subsequent dialyses of the cell extracts. This result indicates that the macromolecule-bound Mn2+ was essentially associated with particulate structures. In contrast to Cu2+, Mn2+ had no effect on the major enzyme activities involved in oxygen metabolism except for a slight increase of cyanide-resistant Mn-superoxide dismutase activity, due to dialyzable Mn2+ complexes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01116194
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Enzyme defense against reactive oxygen derivatives. II. Erythrocytes and tumor cells (1976)
    Springer
    Molecular and cellular biochemistry 10 (1976), S. 11-16 
    Details
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The enzymatic destruction of oxidizing products produced during metabolic reduction of oxygen in the cell (such as singlet oxygen, H2O2 and OH radical) involves the concerted action of superoxide dismutase-which removes O 2 - and yields H2O2-and H2O2 removing enzymes such as catalase and glutathione peroxidase. A difference in distribution or ratio of these enzymes in various tissues may result in a different reactivity of oxygen radicals. It was found that in red blood cells superoxide dismutase and catalase are extracted in the same fraction as hemoglobin, while glutathione peroxidase appears to be “loosely” bound to the cellular structure. This suggests that in red blood cells catalase acts in series with superoxide dismutase against bursts of oxygen radicals formed from oxyhemoglobin, while glutathione & peroxidase may protect the cell membrane against low concentrations of H2O2. On the other hand, catalase activity is absent in various types of ascites tumor cells, while glutathione peroxidase and superoxide dismutase are found in the cytoplasm. However, the peroxidase/dismutase ratio is lower than in liver cells, and this may provide an explanation for the higher susceptibility of tumor cells to treatments likely to involve oxygen radicals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01731676
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The effect of azide on the spectral and catalytic properties of ascorbate oxidase (1975)
    Springer
    Molecular and cellular biochemistry 7 (1975), S. 131-135 
    Details
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary (1) 45% of the total copper of green zucchini ascorbate oxidase is EPR-detectable. At least two species of copper are present, one with a small A∥ (Type 1) and one with a large A∥ (Type 2). Computer simulated spectra indicated 50% contribution by each type of copper. (2) Azide inhibited ascorbate oxidase activity by an uncompetitive mechanism. EPR and optical spectra performed on titration of ascorbate oxidase with azide indicated the formation of a copper-azide complex. The Type 2 copper appears to be the binding site of azide. The involvement of the EPR non-detectable copper as an anion binding site with high affinity toward azide can not be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01792080
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Enzyme defense against reactive oxygen derivatives. II. Erythrocytes and tumor cells (1976)
    Springer
    Details
    Publication Date: 1976-01-01
    Print ISSN: 0300-8177
    Electronic ISSN: 1573-4919
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...