Space biochemistry Final report

During the EURECA mission spores of Bacillus subtilis, conidia of various Aspergillus species, cells of Deinococcus radiodurans, purple membranes of Halobacteria, plasmid pBR322 and small biomolecules have been exposed in the unit ERA to open space conditions, partially also to selected wavelengths of solar UV light. In addition simulation experiments have been performed in the laboratory and the methods for analyzing the molecular causes for the inactivation of microorganisms by opern space conditions have been optimized. It has been found that dormant forms of microorganisms may exhibit half-lives from months to years if exposed to open space in the dark. Ultimately, however, all species become inactivated due to irrevesible damages of chromosomal DNA (especially by formation of DNA-protein cross-links and DNA strand-breaks. Purple membranes, free amino acids and urea were not measurably altered by exposure to space cacuum in the dark. If irradiated in thin layers with high fluences of solar UV light (#propor to#10"8 Joules/m"2), however, significant damages were induced. In constrast, plasmid pBR322 suffered a significant number of DNA strandbreaks, even if exposed to open space conditions in the dark. The effects produced by exposure of microorganisms to open space could be reproduced in the course of the D2 and the Biopan-1 mission. The relative good survival of some species calls for strict observance of COSPAR Planetary Protection Rules. In addition to the 12 publications that appeared or were accepted in the course of the present project, 5 dimploma dissertations and 2 Ph. D. dissertations have been completed. These dissertations, because of their size, are not enclosed. Up to 3 copies of each one can be provided upon request. (orig.)SIGLEAvailable from TIB Hannover: F95B747+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Struktur und Dynamik des Glycoproteins Clusterin (gp80) Schlussbericht

Available from TIB Hannover: DtF QN1(73,34) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Inhibitoren und Modulation des Glykokonjugatmetabolismus durch Zuckeranaloga und Untersuchung einiger dadurch bedingter biologischer Eigenschaften Schlussbericht

1. Components of the cell surface are intimately connected with any processes of cellular information, adhesion and antigenicity. The glycan moiety of these glycoproteins and -lipids play a decisive functional role. Disturbance of these biological processes, e.g. tumor growth, thrombosis, viral infection, immune deficiency, are paralleled by changes of the structure and function of glycans. 2. Chemical, biochemical and biological aims guided this project. Chemically synthesized substances have been used as possible biochemical probe with the aim to influence biological properties of related to the glycan functions as mentioned. 3. For that purpose the development of new synthetic procedures and the use or adaption of known biochemical and biological methods have been essential. 4. More than 100 new substances have been synthesized. Nearly 20% of them have been revealed as biochemically (inhibitors and modulators of glycan or sphingolipid biosynthesis) or biologically active (inhibition of cell proliferation or viral infection). 5. The main goals have been reached. The results are an excellent basis for further research projects to become familiar with hither-to unknown biological functions of glycans and sphingosines with the main goal to introduce thes experience for the development of new therapeutic concepts. (orig.)SIGLEAvailable from TIB Hannover: DtF QN1(22,37) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Entwicklung von in vitro-Stoffwechselsystemen aus tierischer und menschlicher Leber zur Einsparung von Tierversuchen und zur Verbesserung der Uebertragbarkeit auf den Menschen

SIGLEAvailable from TIB Hannover: F94B0757+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Modified calixarenes and new calixarene-like macrocycles

A combined computational (molecular mechanics calculations) and experimental (synthesis, NMR studies, X-ray crystallography) approach was used for the determination of the structure, conformational equilibria and dynamic processes of several novel calixarene derivatives. Calix[4]arenes and calix[5]arenes substituted at one or two of the methylene bridges by alkyl or aryl groups were prepared by (2+2) or (3+2) fragment condensation. NMR data indicate that all these substituted calixarenes adopt a cone conformation. In the alkanediyl calix[4]- and calix[5]arenes, an alkyl substituent at the bridge prefers an equatorial position. In the calix[4]arenes, both the axial and equatorial conformers are populated when the substituent is phenyl, while only the equatorial conformer is present in the calix[5]arenes. The distinct conformational behavior of the phenyl substituent was rationalized in terms of destabilizing steric interactions present in the equatorial conformer of the calix[4]arene derivatives. A calixarene possessing pairs of vicinal exo and endo hydroxyl groups was prepared by fragment condensation. The compound adopts a 1,2-alternate conformation, and its rotational barrier is similar to that of endo-dihydroxycalix[4]arene, indicating that the additional intramolecular hydrogen bond between the exo-OH groups does not decrease the flexibility of the molecule. Solvent-induced conformational shifts were found for two exo-calixarenes. (orig.)Available from TIB Hannover: F00B234 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEGerman-Israeli Foundation for Scientific Research and Development (GIF), Oberschleissheim (Germany)DEGerman