Biotechnological production of unnatural L-amino acids from D,L-5-monosubstituted hydantions. I. Derivatives of L-phenylalanine

Summary Resting cells of a mutant ofArthrobacter sp. (DSM 3747) were used for the bioconversion of D,L-5-benzylhydantoin and related compounds to the corresponding L-amino acids. After optimization of the reaction conditions in shake flask experiments, bioconversions were performed in a preparative scale in a 2-l-bioreactor under nitrogen atmosphere. Specific productivities of 0.4 (p-NO₂-L-phenylalanine) up to 3.9 mM amino acid x g cell dry mass^–1 x h^–1 (p-Cl-L-phenylalanine) were obtained. D,L-5-p-COOH-Benzylhydantoin, D,L-5-phenylhydantoin and D,L-5-p-OH-phenylhydantoin were not accepted as substrates.     

Family studies of hereditary hemochromatosis in Denmark and the Faroe Islands

Summary Pedigree studies were performed based on one Faroese and four Danish probands with overt idiopathic hemochromatosis (IH). The study consisted of HLA typing and determination of biochemical iron status indicators (serum transferrin saturation, serum ferritin). In total, 130 persons were evaluated. The screening identified 6 homozygous (h/h) subjects with preclinical IH, 46 heterozygous (h/n), and 8 normal (n/n) subjects, while 39 subjects were classified as normal or heterozygous (n/h?). One family demonstrated both a homozygous x heterozygous as well as a heterozygous x heterozygous mating. Recombination between the HLA region and IH locus occurred possibly in three subjects in three different families. The significance of detailed screening in families with probands with IH is discussed.     

Shedding of Endogenous Interleukin-6 Receptor (IL-6R) Is Governed by A Disintegrin and Metalloproteinase (ADAM) Proteases while a Full-length IL-6R Isoform Localizes to Circulating Microvesicles

Generation of the soluble interleukin-6 receptor (sIL-6R) is a prerequisite for pathogenic IL-6 trans-signaling, which constitutes a distinct signaling pathway of the pleiotropic cytokine interleukin-6 (IL-6). Although in vitro experiments using ectopically overexpressed IL-6R and candidate proteases revealed major roles for the metalloproteinases ADAM10 and ADAM17 in IL-6R shedding, the identity of the protease(s) cleaving IL-6R in more physiological settings, or even in vivo, remains unknown. By taking advantage of specific pharmacological inhibitors and primary cells from ADAM-deficient mice we established that endogenous IL-6R of both human and murine origin is shed by ADAM17 in an induced manner, whereas constitutive release of endogenous IL-6R is largely mediated by ADAM10. Although circulating IL-6R levels are altered in various diseases, the origin of blood-borne IL-6R is still poorly understood. It has been shown previously that ADAM17 hypomorphic mice exhibit unaltered levels of serum sIL-6R. Here, by quantification of serum sIL-6R in protease-deficient mice as well as human patients we also excluded ADAM10, ADAM8, neutrophil elastase, cathepsin G, and proteinase 3 from contributing to circulating sIL-6R. Furthermore, we ruled out alternative splicing of the IL-6R mRNA as a potential source of circulating sIL-6R in the mouse. Instead, we found full-length IL-6R on circulating microvesicles, establishing microvesicle release as a novel mechanism for sIL-6R generation.     

Die Datenbanken PaleoTax und Goniat - Vorstufen eines paläontologischen Informationssystems

The database systems PaleoTax and GONIAT provide detailed information on literature, taxonomy, morphology and occurrence of fossil invertebrate groups. PaleoTax is designed for Mesozoic corals, GONIAT for Paleozoic ammonoids, but both can be modified to cover other fossil groups. Both systems use dBASE format, but with different database structures. PaleoTax aims at the complete storage of all available objective data, GONIAT provides determinations based upon morphologic criteria, and includes information on geographic distribution and stratigraphic range of every taxon. A combination of both systems could lead to the establishment of a comprehensive paleontological information system useful for research and practical stratigraphic applications.     

Ornithine transcarbamylase (OTC) deficiency in a female patient with a de novo deletion of the paternal X chromosome

Summary A girl with ornithine transcarbamylase (OTC) deficiency was investigated for molecular and cytogenetic abnormalities that might explain this phenotype. Analysis with polymorphic DNA markers indicated that the patient did not inherit paternal alleles of the OTC locus, but that she did inherit the proximal locus DXS7 and the long arm of chromosome X. High-resolution cytogenetic analysis of the patient indicated a deletion of Xp11.4-p21, whereas both parents had normal karytoypes. Since the mother might be heterozygous according to biochemical tests, a second mutation within the maternal OTC gene cannot be excluded.