Crystal and molecular structure of the quinoxaline antibiotic analog TANDEM (des-N-tetramethyltriostin A)

The crystal structure of TANDEM (des-N-tetramethyltriostin A), a synthetic analogue of the quinoxaline antibiotic triostin A, has been determined independently at -135 and 7 'C and refined to R values of 0.088 and 0.147, respectively. The molecule has approximate 2-fold symmetry, with the quinoxaline chromophores and the disulfide cross-bridge projecting from opposite sides of the peptide ring. The quinoxaline groups are nearly parallel to each other and separated by about 6.5 A. The peptide backbone resembles a distorted antiparallel 13 ribbon joined by intramolecular hydrogen bonds N-H(LVal)--O(L-Ala). At low temperatures, the TANDEM molecule is surrounded by a regular first- and second-order hydration sphere containing 14 independent water molecules. At room temperature, only the first-order hydration shell is maintained. Calculations of the interplanar separation of the quinoxaline groups as a function of their orientation with respect to the peptide ring support the viability of TANDEM to intercalate bifunctionally into DNA.

Molecular convergence of hexosamine biosynthetic pathway and ER stress leading to insulin resistance in L6 skeletal muscle cells

Augmentation of hexosamine biosynthetic pathway (HBP) and endoplasmic reticulum (ER) stress were independently related to be the underlying causes of insulin resistance. We hypothesized that there might be a molecular convergence of activated HBP and ER stress pathways leading to insulin resistance. Augmentation of HBP in L6 skeletal muscle cells either by pharmacological (glucosamine) or physiological (high-glucose) means, resulted in increased protein expression of ER chaperones (viz., Grp78, Calreticulin, and Calnexin), UDP-GlcNAc levels and impaired insulin-stimulated glucose uptake. Cells silenced for O-glycosyl transferase (OGT) showed improved insulin-stimulated glucose uptake (P < 0.05) but without any effect on ER chaperone upregulation. While cells treated with either glucosamine or high-glucose exhibited increased JNK activity, silencing of OGT resulted in inhibition of JNK and normalization of glucose uptake. Our study for the first time, demonstrates a molecular convergence of O-glycosylation processes and ER stress signals at the cross-road of insulin resistance in skeletal muscle.

Eine Erinnerung an den 67. Geburtstag des Herrn Sobernheim (in memory of the 67th birthday of Mr. Sobernheim); Wiesbaden Portraits Groups

Participants include Erna Hirsch, Else Giesenow, Marta Nachmann, Erna Goldschmidt (Goldi), Lotte Strauss, Marta Bruchfeld, Toni Eichenberg, Grete Guthmann, Flora Goldschmidt, Hedwig Trum, Hedel Korhmann, Paula Arendt, Erna Behr and Frl. Minka Friedmann

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) for the characterisation of pathogenic leptospires: intra-serovar divergence, interserovar convergence, and evidence of attenuation in Leptospira reference collections.

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) is a novel technology that has emerged as a possible method to characterise leptospires to serovar level. RAPD-HRM has recently been used to measure intra-serovar convergence between strains of the same serovar as well as inter-serovar divergence between strains of different serovars. The results indicate that intra-serovar heterogeneity and inter-serovar homogeneity may limit the application of RAPD-HRM in routine diagnostics. They also indicate that genetic attenuation of aged, high-passage-number isolates could undermine the use of RAPD-HRM or any other molecular technology. Such genetic attenuation may account for a general decrease seen in titres of rabbit hyperimmune antibodies over time. Before RAPD-HRM can be further advanced as a routine diagnostic tool, strains more representative of the wild-type serovars of a given region need to be identified. Further, RAPD-HRM analysis of reference strains indicates that the routine renewal of reference collections, with new isolates, may be needed to maintain the genetic integrity of the collections.

Students on the steps of the Lehranstalt fuer die Wissenschaft des Judentums (Jewish teachers' seminary); Berlin Institutions; Educational; Schools; Portraits; Groups

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Students on the steps of the Lehranstalt fuer die Wissenschaft des Judentums (Jewish teachers' seminary); Berlin Institutions; Educational; Schools; Portraits; Groups

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Students on the steps of the Lehranstalt fuer die Wissenschaft des Judentums (Jewish teachers' seminary); Berlin Institutions; Educational; Schools; Portraits; Groups

Digital Image

Students on the steps of the Lehranstalt fuer die Wissenschaft des Judentums (Jewish teachers' seminary); Berlin Institutions; Educational; Schools; Portraits; Groups

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Komplexe Grundlagenforschung Antijudaismus Verunglimpfung des Judentums in Literatur- und Kirchengeschichte.

Manuscript on Antisemitism in Christianity

Das fatale Loch in der Berliner Theatergeschichte : lecture ueber Persoenlichkeiten des Berliner Theaterlebens und ihre NS-Vergangenheit /

Manuscript: "Das fatale Loch in der Berliner Theatergeschichte". Speech exploring the burdens placed on scholarship and the students of the Theatrical Institute of the Free University of Berlin by the presence of professors who were compromised by their activities during the Nazi era.