The calcium-dependent protease of Loxosceles gaucho venom acts preferentially upon red cell band 3 transmembrane protein

Eighty micrograms red blood cell (RBC) ghosts from patients who had previously exhibited the cutaneous form of loxoscelism (presenting localized dermonecrosis) and the viscerocutaneous form of loxoscelism (presenting dermonecrosis, hemoglobinuria, hematuria, and jaundice) and from controls were incubated with 2.5 µg crude Loxosceles gaucho venom in 5 mM phosphate buffer, pH 7.4, at 37ºC. Among all membrane proteins, quantitative proteolysis of the important integral transmembrane protein 3 increased with venom dose and with incubation time from 30 to 120 min, as demonstrated by gel densitometry. Similar quantitative data were obtained for RBC ghosts from patients and from control subjects, a fact that argues against the possibility of genetic factors favoring the hemolytic viscerocutaneous form. These data suggest that the clinical forms may be different types of the same disease, with the viscerocutaneous form being the result of large amounts of intravascularly injected venom and the superficial form being the result of in situ venom action. Since protein 3 is a housekeeping integral membrane protein, whose genetic deficiency leads to hemolytic anemia, it is reasonable to relate it to the hemolysis which occurs in the viscerocutaneous form of loxoscelism. The venom protease responsible for the process was not inhibited after 120-min incubation by 0.2 mM paramethylsulfonyl fluoride or by 0.2 mM N-ethylmaleimide but was inhibited by 25 mM ethylenediaminetetraacetic acid (a calcium-chelating agent) in 5 mM phosphate buffer at pH 7.4, which suggests that the enzyme is a calcium-dependent metalloprotease.

Functional cell surface expression of the anion transport domain of human red cell band 3 (AE1) in the yeast Saccharomyces cerevisiae.

We expressed the 52-kDa integral membrane domain (B3mem) of the human erythrocyte anion transporter (band 3; AE1) in a protease-deficient strain of the yeast Saccharomyces cerevisiae under the control of the inducible GAL10-CYC1 promoter. Immunoblots of total protein from transformed yeast cells confirmed that the B3mem polypeptide was overexpressed shortly after induction with galactose. Cell surface expression of the functional anion transporter was detected by using a simple transport assay to measure stilbene disulfonate-inhibitable chloride influx into intact yeast cells. The B3mem polypeptide was recycled and degraded by the cells with a half-life of approximately 1-3 hr, which led to a steady-state level of expression in exponentially growing cultures. Our data suggest that 5-10% of total B3mem is functionally active at the cell surface at any one time and that overexpression of this anion transport protein does not interfere with cell growth or survival. This is one of only a few reports of the functional expression of a plasma membrane transport protein in the plasma membrane of yeast cells and to our knowledge is the first report of red cell band 3-mediated anion transport at the plasma membrane of cDNA-transformed cells. The cell surface expression system we describe will provide a simple means for future study of the functional properties of band 3 by using site-directed mutagenesis.

Vitamin E prevents oxidative modification of brain and lymphocyte band 3 proteins during aging.

Antioxidants may play an important role in preventing free radical damage associated with aging by interfering directly in the generation of radicals or by scavenging them. We investigated the effects of a high vitamin E and/or a high beta-carotene diet on aging of the anion transporter, band 3, in lymphocytes and brain. The band 3 proteins function as anion transporters, acid base regulators, C02 transporters, and structural proteins that provide a framework for membrane lipids and that link the plasma membrane to the cytoskeleton. Senescent cell antigen (SCA), which terminates the life of cells, is a degradation product of band 3. This study was conducted as a double-blind study in which eight groups of middle-aged or old mice received either high levels of beta-carotene and/or vitamin E or standard levels of these supplements in their diets. Anion transport kinetic assays were performed on isolated splenic lymphocytes. Immunoreactivity of an antibody that recognizes aging changes in old band 3 preceding generation of SCA was used to quantitate aged band 3 in brain tissue. Results indicate that vitamin E prevented the observed age-related decline in anion transport by lymphocytes and the generation of aged band 3 leading to SCA formation. beta-Carotene had no significant effect on the results of either assay. Since increased aged band 3 and decreased anion transport are initial steps in band 3 aging, which culminates in the generation of SCA and cellular removal, vitamin E prevents or delays aging of band 3-related proteins in lymphocytes and brain.

Differential sensitivity of stilbenedisulfonates in their reaction with band 3 HT (Pro-868-->Leu).

Band 3 HT (Pro-868-->Leu) is a mutant anion exchange protein which has several phenotypic characteristics, including a 2- to 3-fold larger Vmax, and reduced covalent binding of the anion transport inhibitor 4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonate (H2DIDS). We have used fluorescence kinetic methods to study inhibitor binding to band 3 to determine if the point mutation in band 3 HT produces localized or wide-spread conformational changes within the membrane-bound domain of this transporter. Our results show that covalent binding of H2DIDS by band 3 HT is slower by a factor of 10 to 20 compared with the wild-type protein. In contrast, no such difference in the kinetics was observed for covalent binding of 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS). In addition, the kinetics of H2DIDS release from band 3 HT was abnormal, while the kinetics of 4,4'-dibenzamidostilbene-2,2'-disulfonate (DBDS) release showed no difference when compared with the wild-type protein. We conclude that substitution of leucine for proline at position 868 does not perturb the structure of "lysine A" in the membrane-bound domain of band 3 but rather produces an apparently localized conformational change in the C-terminal subdomain of the protein which alters H2DIDS affinity. When combined with the observation of an increased Vmax, these results suggest that protein structural changes at position 868 influence a turnover step in the transport cycle.

Elke Kleinau / Barbara Rendtorff (Hrsg.): Differenz, Diversität und Heterogenität in erziehungswissenschaftlichen Diskursen. Schriftenreihe der Sektion Frauen- und Geschlechterforschung in der Deutschen Gesellschaft für Erziehungswissenschaft(DGfE), Band 3, Opladen u.a.: Barbara Budrich Verlag 2013 (156 S.) [Rezension]

Rezension von: Elke Kleinau / Barbara Rendtorff (Hrsg.): Differenz, Diversität und Heterogenität in erziehungswissenschaftlichen Diskursen. Schriftenreihe der Sektion Frauen- und Geschlechterforschung in der Deutschen Gesellschaft für Erziehungswissenschaft(DGfE), Band 3, Opladen u.a.: Barbara Budrich Verlag 2013 (156 S.; ISBN 978-3-8474-0073-8)

Na 1 Nachlass Max Horkheimer, 712 - Entwürfe für ein mögliches Forschungsprojekt über Liberalismus des 19. Jahrhunderts; "Untersuchung des sozialen Klimas in Stadt- und Landkreisen Hessens"; "Betriebsklime. Eine industrie-soziologische Untersuchung aus dem Ruhrgebiet"; Sardemann, Karl: Interview mit einem Juden über sein Leben 1933 bis circa 1953; "Altersbild und Altersvorsorge der Arbeiter und Angestellte" (p. IX 187 - IX 191.1-3)

Entwürfe für ein Mögliches Forschungsprojekt über Liberlaismus des 19. Jahrhunderts; 1953; 1. Typoskript mit eigenhändigen Korrekturen von Theodor W. Adorno; 7 Blatt; 2. Typoskript mit eigenhändigen Korrekturen von Theodor W. Adorno; 3 Blatt; "Untersuchungn des sozialen Klimas in Stadt- und Landkreisen Hessens"; Entwürfe für ein "Handbuch der Methoden zur Messung des sozialen Klimas", nicht veröffentlicht; 1953; 1. Pollock, Friedrich: "Einführung" zum "Handbuch" a) Typoskript mit eigenhändigen Korrekturen; 8 Blatt; b) Typoskript mit eigenhändigen Korrekturen, 5 Blatt; c) Manuskript, "Vorwort"; 5 Blatt; d) Baumert, Gerhard: Entwurf des "Vorworts"; Typoskript mit handschriftlichen Korrekturen, 2 Blatt; e) Baumert, Gerhard: "Notizen zu Vorwort und Einführung des Handbuchs"; Typoskript, 1 Blatt; 2. Inhaltsverzeichnis zum "Handbuch"; 1 Blatt; 3. Pollock, Friedrich: eigenhändige Notizen zur Einführung; 7 Blatt; 4. Pollock, Friedrich: 1 eigenhändiger Brief mit Unterschrift an Theodor W. Adorno, Santa Monica, 21.09.1953; 1 Blatt; "Betriebsklime. Eine industrie-soziologische Untersuchung aus dem Ruhrgebiet" 1954-1956 veröffentlicht als Band 3 der Frankfurter Beiträge zur Soziologie, Frankfurt 1955; 1. Druckfahnen, mit handschriftlichen Korrekturen; 38 Blatt; 2. Korrektur-Notizen zu den Druckfahnen; 4 Blatt; 3. Adorno, Theodor W. [Mitarbeit]: "Grundreiz [Betriebsumfrage)" a) Typoskript mit handschriftlichen Korrekturen, 4 Blatt; b) Typoskript, 5 Blatt; 4. Adorno, Theodor W.: 1 Brief an Max Horkheimer, ohne Ort, 30.06.1954; 1 Blatt; 5. Fragebogen- Entwurf; Typsokript, 2 Blatt; 6. Fragebogen- Entwurf; Typoskript, 2 Blatt; 7. Adorno, Theodor W.: 1 Brief an Max Horkheimer, ohne Ort, ohne Datum [1954]; 1 Blatt; 8. Dirks, Walter: "Notiz über meine Reise nach Köln, Düsseldorf und Essen", 22.02.1955. Typoskript, 2 Blatt; 9. Becker, Hellmut: "Aktennotiz, Betreff: Ersetzung der Pressekonferenz über die Mannesmann-Studie durch in den nächsten Wochen und Monaten aufeinanderfolgende Artikel qualifizierter Korrespondenten", 15.02.1955. Typoskript, 1 Blatt; 10. Adorno, Theodor W.: 1 Brief an Hermann Winkhaus, Mannesmann AG, ohne Ort, 05.03.1956; 2 Blatt; 11. Winkhaus, Hermann, Mannesmann AG: 1 Breifabschrift an das Institut für Sozialforschung, Düsseldorf, 18.07.1955; 12. Presseveröffentlichungen zur Betriebsklima-Untersuchung; 1 Ordner, 13 Blatt; 13. Zeitschriftenartikel und Abschriften von Artikeln zur Betriebsklima- Untersuchung; mit: Becker, Egon: 2 Briefe mit Unterschrift an Max Horkheimer, Frankfurt, 1955; 1 Brief von Max Horkheimer, Zürich, 25.10.1955; Sardemann, Karl: Interview mit einem Juden über sein Leben 1933 bis circa 1953, insbesondere seine Erlebnisse im Konzentrationslager; 1955; 1. Interview; Typsokript, 38 Blatt; 2. Sardemann, Karl: 1 Brief mit Unterschrift an Max Horkheimer, ohne Ort, 15.12.1955; 1 Blatt; "Altersbild und Altersvorsorge der Arbeiter und Angestellten" veröffentlicht als Sonderheft 1 der Frankfurter Beiträge zur Soziologie, Frankfurt 1958.; Zwischenbericht zum Projekt und Material, 1955; 1. Becker, Egon, u.a.: "Zwischenbericht" 10.03.1953; Typoskript, 9 Blatt; mit einem Brief mit Unterschrift von Egon Becker an Max Horkheimer, ohne Ort, 11.03.1955; 1 Blatt; 2. Fragebogen; als Typoskript vervielfältigt, 16 Blatt; 3. Fragebogen; als Typoskript vervielfältigt, 11 Blatt;

Beck, Heinrich/Ismael Quiles (Editores) Entwicklung zur Menschlichkeit durch Begegnung westlicher und östlicher Kultur: Akten d. IV Interkontinentalen Kolloquiums zur Philos. In-sistenzanthropologie, 1 . - 6 . September 1986 an d. Univ. Bamberg, Frankfurt am Main; Bern; New York; París: Lang, 1988 (Schriften zur Tríadik und Ontodynamik; Band 1)

Fil: Matuschka, Daniel von.

Brij Detergents Reveal New Aspects Of Membrane Microdomain In Erythrocytes.

Membrane microdomains enriched in cholesterol, sphingolipids (rafts), and specific proteins are involved in important physiological functions. However their structure, size and stability are still controversial. Given that detergent-resistant membranes (DRMs) are in the liquid-ordered state and are rich in raft-like components, they might correspond to rafts at least to some extent. Here we monitor the lateral order of biological membranes by characterizing DRMs from erythrocytes obtained with Brij-98, Brij-58, and TX-100 at 4 °C and 37 °C. All DRMs were enriched in cholesterol and contained the raft markers flotillin-2 and stomatin. However, sphingomyelin (SM) was only found to be enriched in TX-100-DRMs - a detergent that preferentially solubilizes the membrane inner leaflet - while Band 3 was present solely in Brij-DRMs. Electron paramagnetic resonance spectra showed that the acyl chain packing of Brij-DRMs was lower than TX-100-DRMs, providing evidence of their diverse lipid composition. Fatty acid analysis revealed that the SM fraction of the DRMs was enriched in lignoceric acid, which should specifically contribute to the resistance of SM to detergents. These results indicate that lipids from the outer leaflet, particularly SM, are essential for the formation of the liquid-ordered phase of DRMs. At last, the differential solubilization process induced by Brij-98 and TX-100 was monitored using giant unilamellar vesicles. This study suggests that Brij and TX-100-DRMs reflect different degrees of lateral order of the membrane microdomains. Additionally, Brij DRMs are composed by both inner and outer leaflet components, making them more physiologically relevant than TX-100-DRMs to the studies of membrane rafts.

Autoimmune hemolytic anemia in systemic lupus erythematosus: association with thrombocytopenia

Hematological disturbances are common in systemic lupus erythematous (SLE). Specifically, autoimmune hemolytic anemia (AHA) may manifest in SLE patients at the time of diagnosis or within the first year of the disease. AHA is often associated with thrombocytopenia, lupus nephritis, and central nervous system activity. In this study we investigated these associations in Brazilian patients with SLE. Forty-four consecutive SLE patients who had a history of AHA were age, gender, and disease duration matched with 318 SLE patients without AHA who formed the control group. All patients fulfilled the revised American College of Rheumatology criteria for SLE and were followed-up within our Service. Clinical and laboratorial manifestations were similar in both groups, except for the predominance of leukopenia, thrombocytopenia, and anti-dsDNA on univariate analysis in the AHA group. The multivariate logistic regression model revealed risk only for thrombocytopenia in the AHA group compared to the control group (odds ratio, 2.70; 95% confidence interval, 1.32-5.50). Our results corroborate previous data that AHA in SLE increases the risk of thrombocytopenia in individuals with SLE. This association suggests a common mechanism in AHA and SLE pathophysiologies.

Optimization and inhibition of the adherent ability of Plasmodium falciparum-infected erythrocytes

The vast majority of the 1-2 million malaria associated deaths that occur each year are due to anemia and cerebral malaria (the attachment of erythrocytes containing mature forms of Plasmodium falciparum to the endothelial cells that line the vascular beds of the brain). A "model" system"for the study of cerebral malaria employs amelanotic melanoma cells as the "target"cells in an vitro cytoadherence assay. Using this model system we determined that the optimum pH for adherence is 6.6 to 6.8, that high concentrations of Ca²* (50mM) result in increased levels of binding, and that the type of buffer used influences adherence (Bis Tris > MOPS > HEPES > PIPES). We also observed that the ability of infected erythrocytes to cytoadhere varied from (erythrocyte) donor to donor. We have produced murine monoclonal antibodies against P. falciparum-infected red cells which recognized modified forms of human band 3; these inhibit the adherence of infected erythrocytes to melanoma cells in a doso responsive fashion. Antimalarials (chloroquine, quinacrine, mefloquine, artemisinin), on the other hand, affected adherence in an indirect fashion i.e. since cytoadherence is due, in part to the presence of knobs on the surface of the infected erythrocyte, and knob formation is dependent on intracellular parasite growth, when plasmodial development is inhibited so is knob production, and consequently adherence is ablated.

Analysis and clinical relevance of microparticles from red blood cells.

PURPOSE OF REVIEW: The mechanisms involved in the formation of red blood cell (RBC) microparticles in vivo as well as during erythrocyte storage are reviewed, and the potential role of microparticles in transfusion medicine is described. RECENT FINDINGS: Microparticles release is an integral part of the erythrocyte ageing process, preventing early removal of RBCs. Proteomics analyses have outlined the key role of band 3-ankyrin anchoring complex and the occurrence of selective RBC membrane remodelling mechanisms in microparticles formation. The presence of several RBC antigens, expressed on microparticles, has been demonstrated. The potential deleterious effects of RBC microparticles in transfused recipients, including hypercoagulability, microcirculation impairment and immunosuppression, are discussed. SUMMARY: Formation and role of RBC microparticles are far from being completely understood. Combining various approaches to elucidate these mechanisms could improve blood product quality and transfusion safety. Implementation of RBC microparticles as biomarkers in the laboratory routine needs to overcome technical barriers involved in their analysis.

The combined use of reflectance, emissivity and elevation Aster/Terra data for tropical soil studies

Reflectance, emissivity and elevation data of the sensor ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)/Terra were used to characterize soil composition variations according to the toposequence position. Normalized data of SWIR (shortwave infrared) reflectance and TIR (thermal infrared) emissivity, coupled to a soil-fraction image from a spectral mixture model, were evaluated to separate bare soils from nonphotosynthetic vegetation. Regression relationships of some soil properties with reflectance and emissivity data were then applied on the exposed soil pixels. The resulting estimated values were plotted on the ASTER-derived digital elevation model. Results showed that the SWIR bands 5 and 6 and the TIR bands 10 and 14 measured the clay mineral absorption band and the quartz emissivity feature, respectively. These bands improved also the discrimination between nonphotosynthetic vegetation and soils. Despite the differences in pixel size and field sampling size, some soil properties were correlated with reflectance (R² of 0.65 for Al2O3 in band 6; 0.61 for Fe2O3 in band 3) and emissivity (R² of 0.65 for total sand fraction in the 10/14 band ratio). The combined use of reflectance, emissivity and elevation data revealed variations in soil composition with topography in specific parts of the landscape. From higher to lower slope positions, a general decrease in Al2O3 and increase in total sand fraction was observed, due to the prevalence of Rhodic Acrustox at the top and its gradual transition to Typic Acrustox at the bottom.