Search Results - (Author, Cooperation:B. Stieglitz)

2013-10-22

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Apoproteins/chemistry/metabolism ; Catalytic Domain ; Crystallography, X-Ray ; HeLa Cells ; Humans ; Models, Molecular ; Protein Conformation ; Substrate Specificity ; Ubiquitin/*chemistry/*metabolism ; Ubiquitin-Protein Ligases/*chemistry/*metabolism

2011-04-02

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; *Apoptosis/drug effects ; B-Lymphocytes/metabolism ; Carrier Proteins/metabolism ; Caspase 8/metabolism ; Cells, Cultured ; Dermatitis/genetics/metabolism/pathology ; Fas-Associated Death Domain Protein/metabolism ; Fibroblasts/metabolism ; HEK293 Cells ; HeLa Cells ; Humans ; I-kappa B Kinase/metabolism ; Intracellular Signaling Peptides and Proteins/metabolism ; Macrophages/metabolism ; Mice ; NF-kappa B/*metabolism ; Nerve Tissue Proteins/deficiency/genetics/*metabolism ; Tumor Necrosis Factor-alpha/metabolism/pharmacology ; Ubiquitin/*metabolism ; Ubiquitin-Protein Ligase Complexes/*metabolism ; Ubiquitin-Protein Ligases/metabolism ; Ubiquitination

1432-0614

Springer Online Journal Archives 1860-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

Abstract Pseudomonas putida NRRL-18668 contains a nitrile hydratase capable of stereoselective hydrolysis of 2-(4-chlorophenyl)-3-methylbutyronitrile at more than 90 % enantiomeric excess (ee) to the (S)-amide. This soil isolate was recovered from enrichments using (R,S)-2-methylglutaronitrile as the sole nitrogen source. Enzyme expression is constitutive and does not show a high level of catabolite repression. The organism is capable of growth on a wide variety of aliphatic mono- and dinitrile compounds. The hydrolysis activity on propionitrile is approximately 10.3 μmole h−1 mg wet cells−1. The enzyme in cell-free preparations is inhibited by a number of heavy metals, phenylhydrazine, and cyanide. Substrate specificity is broad with highest rates shown on C4 and C5 aliphatic mononitriles. The strain appears somewhat unusual in its dependence on cobalt supplementation for maximum enzyme activity and the ability to hydrolyze some aromatic nitriles. This strain is also capable of a two-step hydrolysis of 2-(4-isobutylphenyl)-propionitrile and 2-(6-methoxy-2-napthyl)-propionitrile to the (S)-acids (ibuprofen and naproxen respectively) with stereoselectivity residing primarily in the aliphatic amidase. This appears to be the first description of a steroselective nitrile hydratase from a gram-negative organism.

Electronic Resource

0006-3592

Chemistry ; Biochemistry and Biotechnology

Wiley InterScience Backfile Collection 1832-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

Two instruments were developed to mechanize the handling of anaerobic microorganisms for microbial mutant isolation. The instruments automatically dispense liquid or agar medium to large and small 96-well platesand petridishes. Protocols were developed for inoculating different microorganisms, and calibration curves of number of areas or wells inoculated versus cell concentration were prepared for bacteria, yeast and fungi (spores). Experiments with yeast auxotrophic mutants and fungal spores showed that microbe inoculation follows Poisson statistics in distributing a single microorganism per inoculation point. The isolation and identification of Yarrowia lipolytica auxotrophic, morphological, and temperature-sensitive or tolerant mutants demonstrated the use of the instruments for microbial screening.

8 Ill.

Electronic Resource